User:Rezalon/Sandbox2

"Time, Doctor Freeman? Is it really that time again?"

― The G-Man

The known timeline of the Half-Life and Portal universe spans mostly from Earth's 20th century to its far future. This timespan sees the rise and fall of rival scientific research corporations Aperture Science and Black Mesa, the Combine's invasion and occupation of Earth in the aftermath of the Black Mesa Incident, and the uprising of humanity against them.

On issuing precise dates on an official timeline, Marc Laidlaw, former lead writer at Valve, stated the company doubted they ever would because of the possibility of contradicting themselves in the future.

The following timeline has been constructed by gathering every established date found and the events that have transpired in the series. Several retcons have been made since the first Half-Life game released in 1998, so more recent developments may contradict older material. Additionally, the events of Half-Life: Alyx indicate the storyline does not always occur linearly as events in both the series' past and future can be further manipulated. Some in-universe dates are based on real-world information, and as such may not reflect series canon; these are denoted with the Valve logo ().

18th Century

1770s

Between 1773 and 1782

• The Terminal publishes its first issue.

• 

  The Terminal logo, 200-.

19th Century

1860s

1860

• The vodka brand Chatka is established in Saint Petersburg, Russia.

• 

  Chatka billboard ad.

1870s

Between 1874 and 1883

• The Times publishes its first issue.

• 

  The Times logo, 200-.

1890s

1891

• Year engraved on several metal railings found in City 17, and St. Olga. (Non-canonical appearance)

• 

1892

• The beer brand Bashkir is established in Sterlitamak, Russia.

• 

  Bashkir bottle.

1897

• The European-style lager beer brand Chesterfield is established.

• 

  Chesterfield bottle.

20th Century

1900s

1901

• The canned fish brand Delicious Fish is established.

• 

  Delicious Fish can.

1930s

Between 1936 and 1937

• One version of Cave Johnson is born. He is 51 during the events of the Perpetual Testing Initiative, set in 1988. (Non-canonical appearance)

1937

• The semi-sweet red wine brand Kurdzhips is established.

• 

  Kurdzhips label.

1940s

1943

• By now, Cave Johnson has founded Aperture Fixtures, primarily manufacturing shower curtains for the US military, with Johnson receiving the Shower Curtain Salesman award within Aperture. Early product line provides a very low-tech portal between the inside and outside of consumers' showers.

• 

1944

• On January 6, Cave Johnson appears in The UP Pioneer Press headlines for buying a salt mine in Upper Michigan.

• 

Between 1944 and 1954

• Richard Keller is born. He is 55 during the events of Half-Life: Decay, set in 200-.

• 

  Keller, aged 55.

1947

• Aperture Science Innovators is established and receives the award for Best New Science Company from the Science and Business Institute of America.

• 
• 

Between 1947 and 1957

• Wallace Breen is born. He is 52 during the events of Half-Life, set in 200-, and the immediately following Seven Hour War.

• 

  Portrait of Breen from The Terminal, aged 52.

1949

• Aperture Science is rated #2 among the Top 100 Applied Science Companies by Mechanical Engineering World Journal.

• 

1950s

• It is during this decade the Black Mesa Research Facility is built on top of several decommissioned ICBM launch and testing silo complexes.

• 

  Photo of Black Mesa, New Mexico.

• 

  Portrait of Cave Johnson during this decade.

1952

• Aperture Science constructs Test Shaft 09's Entrance Way, Lobby and Testing Lounge, and Pump Station Alpha for the testing of Repulsion Gel no earlier than this year.
• Aperture is the runner up of the US Department of Defense's Contractor of the Year award.
• Around now, Aperture has inadvertently created an "army of Mantis Men" by injecting test subjects with praying mantis DNA.

• 
• 

  Exterior of Pump Station Alpha.

• 
• 

  Mantis Man bobblehead. (Non-canonical appearance)

1953

• Aperture Science's secondary R&D efforts focus on primitive portal technology and Repulsion Gel. The fledgling portal technology is bulky and haphazard; poor surface conductors for portal placement lead to frequent mishaps and test subject mangling and death. The portal device is known as the Aperture Science Portable Quantum Tunneling Device.
• Aperture constructs Test Shaft 09's Enrichment Sphere 01's Test Chamber 01, and begins construction on Chamber 02.

• 

  Poster depicting test subject armed with an ASPQTD.

• 

  Repulsion Gel in situ.

• 
• 

1954

• Aperture Science is the runner up of the US Department of Defense's Contractor of the Year award again.

• 

1955

• Aperture Science receives the National Potato Board's "Spirit of Idaho" award for the promotion of Potato Science.

• 

1956

• The Eisenhower administration awards Aperture Science a contract to provide shower curtains to all branches of the US military except the Navy, while leading astronauts, war heroes, and Olympians are invited to Aperture to help with the testing of ground-breaking inventions.
• By now, Pump Station Alpha is in active use, with Aperture finishing construction on Test Shaft 09's Enrichment Sphere 01's Test Chamber 02.

• 
• 

1957

• Aperture Science constructs Test Shaft 09's Enrichment Sphere 02's Test Chamber 02.
• From now until 1973, Aperture produces mostly shower curtains.

• 

1958

• By now, Aperture Science's Repulsion Gel, being marketed as "Repulsion Pudding", is pulled from shelves "for various reasons". No longer being sold as a dietetic pudding substitute, Aperture revamps and continues experimentation on it as a testing element.
• Aperture begins forming control groups for experimentation with cranial microchip implantation.
• Aperture constructs Test Shaft 09's Enrichment Sphere 03's Test Chambers 27 and 28, and around now has begun testing on time travel.

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• 
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• 

1960s

1961

• On June 15, Aperture Science's Test Shaft 09 "Zulu Bunsen" is condemned, abandoned and sealed off.

• 
• 
• 

  Test Shaft 09 abandonment hatch.

1968

• Aperture Science becomes "a vital participant" in the US Senate hearings on missing astronauts.

Between 1968 and 1978

• Colette Green is born. She is 31 during the events of Half-Life: Decay, set in 200-.

• 

  Green, aged 31.

1970s

• It is during this decade Grady and an otherwise unnamed Aperture Science employee later working under the witness protection program as "Charlie" accidentally invent "toilet turrets", (Non-canonical appearance) which would eventually be further developed by Aperture into the Aperture Science Sentry Turret.

• 

  Aperture logo during this decade.

• 

  Portrait of Cave Johnson during this decade.

• 

  Ditto, with assistant Caroline.

• 

  Grady presenting Mk. I toilet turret to "Charlie". (Non-canonical appearance)

1971

• Aperture Science re-opens Test Shaft 09 and constructs Pump Station Beta for the testing of Propulsion Gel and a new entrance way, and a drydock for experimenting on a research icebreaker in a competing bid (against Black Mesa) over a Defense Logistics Agency contract for an effective FSII solution no earlier than this year.
• Around now, Aperture has gone bankrupt.

• 
• 
• 

  Underground drydock.

1972

• Aperture Science constructs Test Shaft 09's Enrichment Sphere 04's Test Chambers 01 and 02.

• 
• 

Between 1972 and 1982

• Gordon Freeman is born. He is 27 during the events of Half-Life, set in 200-.

• 

  Freeman, aged 27.

1973

• Earliest known use of a bulletin board system by Aperture Science.
• Aperture no longer produces mostly shower curtains.

1974

• Cave Johnson secretly develops a dangerous mercury-injected rubber sheeting, from which he plans to manufacture seven deadly shower curtains to be given as gifts to each member of the House Naval Appropriations committee.

Between 1974 and 1984

• Gina Cross is born. She is 25 during the events of Half-Life: Decay, set in 200-.

• 

  Cross, aged 25.

1975

• A Lane Electronics circuit connector is manufactured.

• 

1976

• Aperture Science constructs Test Shaft 09's Enrichment Sphere 05's Test Chamber 05.
• By October 17, Cave Johnson realizes that testing on prominent members of society can be problematic, especially if they go missing. In response to this realization, he profiles what he deems as "low risk" test subjects. His profile is released internally in a confidential memo to select Aperture Science employees.

• 
• 

Between 1977 and 1987

• Adrian Shephard is born. He is 22 during the events of Half-Life: Opposing Force, set in 200-.

• 

  Shephard, aged 22.

1978

• Due to financial difficulties and possible legal problems arising from testing prominent citizens, Aperture Science begins using homeless people as test subjects. Aperture's object of testing and experimentation at this time is Propulsion Gel, no longer being considered as a "Propulsion Pudding" dietetic aid successor to Repulsion Pudding. Complementing this, Aperture begins experimenting with human deconstruction, enhancement, and reconstruction procedures.
• Aperture constructs the elevator to the surface from the Propulsion Gel testing section of Test Shaft 09.

• 

  Egregious depiction of homeless Aperture test subject.

• 

  Propulsion Gel in situ.

• 

Between 1978 and 1988

• At the age of six, Gordon Freeman constructs a butane-powered tennis ball cannon.

1979

• Interested in the superior portal conductor properties of moon rocks, Cave Johnson acquires $70 million worth of the lunar material. In experimenting with this, he grinds it up and mixes it into a new gel he calls Conversion Gel. Unfortunately, Johnson soon discovers that ground up moon rocks are highly poisonous and he begins to become deathly ill.

• 

  Moon rock.

1980s

• 

  Aperture (dba Aperture Laboratories) logo used from this decade onward.

• 

  Portrait of Cave Johnson during this decade.

1980

• Both of Cave Johnson’s kidneys fail. Brain damaged, dying, and incapable of being convinced that time is not now flowing backwards, Johnson lays out a three-tier R&D program. The results, he says, will “guarantee the continued success of Aperture Science far into the fast-approaching distant past.”:

1. The Heimlich Counter-Maneuver – A reliable technique for interrupting the life-saving Heimlich Maneuver.

2. The Take-A-Wish Foundation – A charitable organization that will purchase wishes from the parents of terminally ill children and redistribute them to wish-deprived but otherwise healthy adults.

3. Improved portal technology that he cryptically refers to as “Some kind of rip in the fabric of space…that would…well, it’d be like, I don’t know, something that would help with the shower curtains I guess. I haven’t worked this idea out as much as the wish-taking one.”

1981

• Diligent Aperture Science engineers complete the Heimlich Counter-Maneuver and Take-A-Wish Foundation initiatives. The company announces products related to the research in a lavish, televised ceremony. These products immediately become wildly unpopular. After a very public string of choking and despondent sick child disasters, senior company officials are summoned before a Senate investigative committee. During these proceedings, an engineer mentions that significant progress has been made on "Tier 3", the “man-sized ad hoc quantum tunnel through physical space with possible applications as a shower curtain.” The committee is quickly and permanently recessed, and Aperture is granted an open-ended contract to secretly continue research on portal technology and the "Heimlich Counter-Maneuver" project.
• Aperture constructs a new Test Subject Waiting Area, around now using its own employees as test subjects, replacing any lost with robot workers.

• 
• 
• 
• 
• 
• 

1982

• Increasingly ill, Cave Johnson pushes forward with the new Conversion Gel. By painting surfaces with a paint made from the gel, safe and stable portals can be placed and traversed with no harm coming to the test subject. Due to his illness, Johnson also becomes interested in artificial intelligence and brain mapping. His hopes are that a successful brain map would allow a person's intelligence and consciousness to be implanted into a computer. In particular, he sees this as a possible way to overcome his poisoning and defeat death. Johnson states that if he dies before work is complete, his assistant Caroline is to succeed him as CEO of Aperture Science and have her consciousness put into a computer, even against her will.
• Earliest known use of the Enrichment Center Test Subject Application Process being applied to Aperture's test subjects. It is operated by version 1.07 of Aperture's in-house "GLaDOS" disk operating system, later upgraded to versions 1.07a and 1.09.
• Aperture constructs Test Shaft 09's Pump Station Gamma and Enrichment Sphere 06's test chamber.
• An image of a cake celebrating October 29 is among several images in GLaDOS' databanks.

• 

  Conversion Gel in situ.

• 
• 
• 
• 

1983

• From now to 1985, work progresses on Aperture Science's “Portal” project. Several high ranking Fatah personnel choke to death on lamb chunks despite the intervention of their bodyguards.
• Aperture publishes a "Girls of Aperture Science" calendar.
• Images of cakes celebrating October 1 and 19 November, respectively, are among several images in GLaDOS' databanks.

• 

  Calendar defaced with picture of a Companion Cube.

• 
• 

1984

• Images of cakes celebrating 11 August and September 15, respectively, are among several images in GLaDOS' databanks.

• 
• 

1985

• Earliest known use of the Aperture Image Format.
• An image of a cake celebrating 27 September is among several images in GLaDOS' databanks.

• 

1986

• Word reaches Aperture Science management that competing and rival defense contractor Black Mesa is working on similar portal technology. In response to this news, Aperture begins further developing their GLaDOS to be used as an artificially intelligent research assistant (or "genetic lifeform") and disk operating system.
• Test Shaft 09's Enrichment Sphere 06's test chamber is fitted with a new wall.
• The animal feed brand Duke is established.
• A toy rocket signed "Paul P." is dated to this year.
• An image of a cake celebrating February 8 is among several images in GLaDOS' databanks.

• 

  Black Mesa logo in GLaDOS' databanks.

• 
• 

  Duke animal feed bag.

• 
• 

1987

• Latest known use of the Aperture Image Format.

1988

• A number of versions of Aperture Laboratories across the multiverse near bankruptcy and each establish their own Extra-Earth Outsourcing and Perpetual Testing Initiative. (Non-canonical appearance)

• 

1989

• A prototype chassis for GLaDOS is constructed, but it is subsequently abandoned.
• Aperture Science, dba The Lab, begins testing on pocket universes. (Non-canonical appearance)

• 

  GLaDOS' original prototype chassis.

• 

1990s

1994

• On January 21, 25, and 28, several Aperture Laboratories employees sign a blueprint of the Borealis.

• 

Between 1995 and 2005

• Alyx Vance is born. She is 19 during the events of Half-Life: Alyx, set between 2015 and 2024.

• 

  Photo of infant Alyx, with parents Azian and Eli.

1996

• After a decade spent bringing the Disk Operating System parts of GLaDOS to a state of basic functionality, Aperture Science begins work on the Genetic Lifeform component. To implement the Genetic Lifeform component, the essence of Caroline is infused into the existing OS to provide the basis for GLaDOS' thought process. Around now, while GLaDOS is being developed, it is somebody's job to sit by a red phone in her chamber, and, if it ever looked like the AI was becoming sentient and godlike, or otherwise rogue, that person would pick up the phone and dial extension 219 for assistance.

• 

  Red phone in GLaDOS' chamber.

Late 1990s

• While visiting the University of Innsbruck, Gordon Freeman observes a series of seminal teleportation experiments conducted by the Institute for Experimental Physics. Practical applications for teleportation become his obsession.

1997

• Latest known use of a bulletin board system by Aperture Laboratories. By now, GLaDOS is version 3.11.

• 

1998

• Aperture Science, dba Aperture Laboratories, releases several testing elements, including: the Aerial Faith Plate, the consumer version of the Aperture Turret, Excursion Funnel, Pneumatic Diversity Vent, Propulsion Gel, Quantum Tunneling Device, Repulsion Gel, and Thermal Discouragement Beam. Aperture also releases an Evacuation Training Service Announcement video.
• From January 5 to August 16, in the Eastern European city that would later become City 17, an exhibit on young masters of ink on paper from the 1870-1930 period is held at the National Art Gallery in cooperation with the Chistyakov Fund. The entrance is free, and it is open on weekdays and Sundays from 10 a.m. to 5 p.m., and on holidays.
• In December, the "extreme" tarragon-flavored Grunge soda is labeled "Flavor of the Month".

• 
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  Designer colors available for consumer version of Aperture Turret.

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  Grunge soda can label.

1999

• Gordon Freeman receives his doctorate from M.I.T. with a thesis paper entitled Observation of Einstein-Podolsky-Rosen Entanglement on Superquantum Structures by Induction through Nonlinear Transuranic Crystal of Extremely Long Wavelength (ELW) Pulse from Mode-Locked Source Array.
• A woman named Sarah takes a photo of her cat Beatrice.
• From September 25 to March 12, 2000, in the Eastern European city that would later become City 17, an exhibit on "Tyrannosaurus rex - The ultimate predator" is held at the Museum of Natural History (MNH) at the Barracks, in the newly renovated Prehistoric Hall. Admission is free for children under the age of twelve, and it is open from Tuesdays to Saturdays from 10 a.m. to 6 p.m., and on Sundays from 11 a.m. to 4 p.m.
• On November 1, the US War Department issues its Soldier's Field Manual handbook.

• 

  Freeman's doctorate in his locker at Black Mesa, 200-.

• 
• 
• 

Between 1999 and 2008

• Chell makes a potato battery for her class project.

2000

• On January 13, the US War Department issues an updated copy of its Basic Field Manual soldier's handbook.

21st Century

2000s

2001

• On December 5, the keycard of Terminal Authority employee Fyodor Todorova was set to expire. The card is ultimately never invalidated after this date, as Alyx Vance ends up using it over a decade later.

• 

2002

• On September 28, the keycard of Terminal Authority employee Zdravka Damyanovska was set to expire. The card is ultimately never invalidated after this date, as Alyx Vance ends up using it over a decade later.

• 

2006

• An image of a cake celebrating 4 July is among several images in GLaDOS' databanks.

• 

200-

• Russell applies for a job at the Black Mesa Research Facility. His application is rejected and is told to reapply the following year; this never occurs because of the Black Mesa Incident.

March

• Cpl. Adrian Shephard pens several entries in his diary:

• "March 3rd: Another typically hellish day at base camp... I'll be glad when this is over and I can get assigned a mission. There has been this really weird civie spotted at the base. Rumor is he's from some government branch looking to recruit; others say he's with some secret research group. I would jump at the chance to join. It would be cool just for the change and the adventure."
• "March 7th: I finally saw the government guy today. I'm not sure he is a g-man, but he was wearing a really uptight suit and carrying a briefcase. He looked more like a lawyer or insurance agent to me. I did notice him checking me out. Several times throughout the day I spotted him just watching me during training. I wonder what he's up to..."
• "March 9th: For weeks our drills have been the same crap day after day. Today we assemble for the morning run and our drill instructor tells us we have one week to become experts at indoor strategic combat. We will be spending every day this week at the combat simulation facility. As far as I know this a specialized training not taught in boot camp. What I want to know is if this is to test our ability to adapt or if we are being readied for a specific mission? Time will tell..."
• "March 12th: The rumors have been flying since our indoor combat training began. Most of my peers are convinced that we are being primed for a mission. No one can agree on what the mission is. I have heard the name Black Mesa Facility thrown around a lot, but I have no information about the place. The rumors are that some top-secret research is going on there. Doesn't sound too exciting to me..."
• "March 15th: The rumor has been confirmed. We are being trained for a mission at the Black Mesa Facility. All I know is that the place is being used by scientists who are doing some kind of new research. I can't imagine what we would be needed for. We were told today to be ready in case it happens tomorrow. I don't know what "it" is, but the whole thing is a little strange. I kind of hope it doesn't happen; the mission doesn't seem to have much excitement potential. I'd rather hold out for something with more likelihood of combat."

• 
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  Santego Military Base.

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  "G-man" observing Shephard.

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  Senior Drill Instructor Dwight T. Barnes.

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  A few of Shephard's peers of the Hazardous Environment Combat Unit.

• 

"Mere weeks" before the Seven Hour War

• The global market is "soaring", with investors "riding high".

May 5

• While concluding his affairs at the University of Innsbruck, Dr. Gordon Freeman is sent a letter from the Black Mesa Office of the Administrator's L.M. confirming his acceptance for a position at the Research Facility. Dr. Judith Mossman, who was up for the same job as Freeman, is edged out with his Innsbruck experience and Dr. Isaac Kleiner's personal recommendation.

• 
• 
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  Mossman, 202-.

• 

  Picture of Kleiner from Popular Scientist.

"A week" before May 16

• Suspected period an ichthyosaur was claimed to have been "hauled" from the Challenger Deep to Black Mesa.

• 

  Ichthyosaur.

"Days" before May 16

• Around now, Aperture Science's research icebreaker the Borealis and part of its drydock disappear during testing and development. The events surrounding the Borealis become highly classified.
• The untested GLaDOS AI is activated for the first time as one of the planned activities on Aperture's first annual Bring Your Daughter to Work Day. In many ways, the initial test goes well: Immediately, within one picosecond of being switched on, GLaDOS becomes self-aware. The "going well" phase lasts for two more picoseconds, at which point GLaDOS takes control of the facility and locks it down, trapping everyone inside. She then deploys a deadly neurotoxin which kills the majority of the scientists within the facility. A few survivors manage to install a Morality Core into GLaDOS which prohibits her from using the neurotoxin again. With the Morality Core in place, GLaDOS turns her attention back to the facility and begins testing. Her goal: beat the hated Black Mesa in the race to develop a functioning portal technology.

• 

  Borealis after its disappearance.

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  BYDTWD exhibition.

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  Chell's potato experiment for the BYDTWD science fair.

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  Depiction of GLaDOS' activation.

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  Morality Core attached to GLaDOS.

May 9

• Barney Calhoun is sent a letter from L.M. regarding his reassignment to the Black Mesa Security Force's Blue Shift effective May 15.

• 
• 

  Calhoun.

May 11

• Dr. Colette Green is sent a letter from L.M. informing her of Black Mesa senior staff's decision that sample GG-3883 will replace EP-0021.

• 
• 

  GG-3883.

May 12

• By now is Barney Calhoun processed for a salary increase and retinal scan, and his two-day training course is scheduled.
• At 8:00 AM, Calhoun begins the first day of his two-day Security Guard training under security officer Miller's holographic assistant counterpart.

• 
• 

  Miller's hologram.

May 13

• Second day of Barney Calhoun's two-day training course.
• At 10:30 AM, Dr. Walter Bennet is being trained by Dr. Gina Cross for an Anti-Mass Spectrometer Overload Simulation.

• 
• 

  Bennet.

• 

  Anti-Mass Spectrometer.

May 14

• At 19:00 AM, Colette Green was to be trained by Isaac Kleiner on Anomalous Materials Handling, but this is rescheduled to June. This never occurs because of the Black Mesa Incident.

• 

May 15

• The latest date Gordon Freeman would take on his position at Black Mesa.
• At 9:00 AM, Barney Calhoun reports to the Sector C Area 3 Medium Security Facilities' section manager where he is provided his assignment. Calhoun is assigned to a 0900 - 2200 Blue Shift until August 15. Various other security officers are assigned to Red, Orange, Yellow, Green and Indigo Shifts throughout various areas and times in the facility, respectively, while Violet Shift is on standby.
• At 20:00 PM, Gina Cross is being trained by Dr. Richard Keller on an HEV Mk. 5 Prototype.

• 
• 
• 

  HEV Mk. 5 suit.

May 16

Morning

• At 7:30 AM, Gordon Freeman is being trained by Gina Cross' holographic counterpart on the Hazardous Environment Suit in the Black Mesa Training Facility. Prior to the training run, the scientists monitoring Freeman mention that the sensors in their equipment are not working, and "things are in a state of commotion".
• The experiment on sample GG-3883 in the anti-mass spectrometer was to be performed at 8:30 AM, but this is delayed by at least half an hour due to Freeman running late to work.
• Further system crashes and security malfunctions occur throughout Sector C at "about" 8:40 AM.
• At 8:42 AM, Barney Calhoun begins his tram ride from the Area 8 Topside Dormitories to start his second day of Blue Shift.
• At approximately 8:46 AM, Calhoun passes Freeman waiting on a Level 3 Dormitories tram platform.
• At 8:47 AM, Freeman begins his tram ride. He passes Calhoun banging on a door to the Sector C Area 3 Medium Security Facilities; topside temperature is 93° Fahrenheit.
• At approximately 9:00 AM, Calhoun gears up for his shift and receives orders to travel to Sector G to see what he can do about restoring power to its main access lift for two stuck scientists. Viewing a security feed, Calhoun witnesses Freeman arriving at the Anomalous Materials Laboratory "about half an hour" late, as well as Gina Cross preparing sample GG-3883 for the experiment.
• On his way to gearing up in his HEV suit, Freeman destroys Dr. Arne Magnusson's microwave casserole in the lab's cafeteria.

• 
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  Cross' hologram, wearing HEV Mk. 4 suit.

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  Calhoun boarding tram.

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  Calhoun banging on door.

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  Freeman passing Calhoun.

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  Freeman arriving to work.

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  Cross preparing the sample.

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  Magnusson's casserole post-destruction.

The Resonance Cascade

• Moments after Gordon Freeman enters the test chamber, the "G-Man" approaches Dr. Eli Vance and whispers to him a warning: "prepare for unforeseen consequences".
• Beneath the anti-mass spectrometer's chamber, Colette Green brings it online and powers it up to 80%. In the chamber itself, Freeman concurrently starts its rotors.
• The Anomalous Materials team monitoring the experiment's progress power the stage one emitters. Seeing predictable phase arrays, the team activate stage two emitters and, despite the team's objections to Administrator Dr. Wallace Breen, has Gina Cross disengage the safety locks in order to increase power to 105%. Initially concerned by a small discrepancy in their monitoring equipment, it returns within acceptable bounds and the team sustains sequence, informing Freeman the non-standard specimen is ready for standard insertion.
• Freeman pushes the sample into the anti-mass spectrometer, creating a resonance cascade. The team fails to shut down the equipment, and several of its members are injured or killed as the equipment around them explodes. Alien creatures begin teleporting in and out of the chamber from Xen, as does Freeman himself, until he passes out for several hours. Beneath the chamber, doctors Cross and Green too fall unconscious.
• Meanwhile, Barney Calhoun witnesses the effects of the resonance cascade after restoring power to Sector G's main access lift for two stuck scientists, with varieties of Xen lifeforms teleporting into the facility and major equipment malfunctions causing several injuries and deaths. The main access lift fails and falls to the bottom of its shaft, killing the two scientists and knocking Calhoun out.

• 

  Stage One emitters.

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  Stage Two emitters.

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  Resonance Cascade teleporting Vortigaunts to Earth.

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  Freeman teleported to Xen.

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  Resonance Cascade from Cross' perspective.

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  Ditto, from Calhoun's perspective.

Remainder of the morning

• Gina Cross and Colette Green regain consciousness. Arming themselves, they fight against alien creatures through the corridors beneath the anti-mass spectrometer to reach doctors Rosenberg and Richard Keller in the control room. While Keller decides to remain to assess the damages received by the equipment, the other three elect to find their way to the surface to call for military assistance.
• The Experimental Propulsion Laboratory was to perform a test fire at 10:30 AM, but this never occurs because of the Resonance Cascade.
• The Cryogenic Safety Crew was to report status at 11:00 AM, but this presumably never occurs because of the Resonance Cascade.

• 

  Beneath the anti-mass spectrometer after the Resonance Cascade.

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  Scene witnessed by Cross and Green on their way to the control room.

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  The four doctors form a plan.

Afternoon

• Gina Cross and Colette Green escort Rosenberg through the ruined Black Mesa Training Facility in order to reach the surface.
• Meanwhile, Gordon Freeman regains consciousness in the anti-mass spectrometer test chamber. With the phone lines cut out, Eli Vance tasks Freeman with getting himself to the surface and seeking help for the science team stranded in the facility.

• Some time after assisting Freeman in the aftermath of the resonance cascade, Vance manages to escape the facility with his young daughter Alyx Vance, who is saved due to intervention by the G-Man; Vance's wife Azian perishes during the Black Mesa Incident. Alyx, a family picture and his wedding ring are all he manages to carry out of Black Mesa.

• Cross, Green, and Rosenberg reach the Satellite Communications Center, where they align the satellite uplink dish and send an emergency signal to the military. Cross and Green then make their way back to the Anomalous Materials labs to meet back up with Richard Keller.
• Freeman fights his way through various Xen lifeforms and zombified members of the science team in Sector B's Coolant Reservoir Facility and Sector D's Administration Center.
• During this time, the HECU arrives at Black Mesa, having been ordered by the United States government to kill all alien forces and Black Mesa personnel as containment. This includes Adrian Shephard's unit, whose Osprey is attacked by alien craft. During the chaos, Shephard loses and regains consciousness until the next day.
• By now, Barney Calhoun regains consciousness, fighting through Xen lifeforms and zombies in the tunnel systems of Sector G, searching for a way to the surface.

• 

  Ruined Hazard Course.

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  Ground Zero of the Incident.

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  Vance (right) post-Cascade.

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  Rosenberg contacting the military.

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  Coolant Reservoir Facility post-Cascade.

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  Scientists attempting to escape Administration Center.

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  HECU Osprey attacked by alien craft.

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  Calhoun's first sight regaining consciousness.

Dusk

• Gina Cross and Colette Green return to Richard Keller, where they re-engage the anti-mass spectrometer's dampening fields in hopes of ending the resonance cascade. The fields fail, with Keller discovering the cause being intentional interference coming from the other side of the rift, speculating the arrival of the alien lifeforms may not be accidental.
• Having climbed his way to Sector D's High Security Materials Storage Area, Gordon Freeman sees his first encounter with the HECU. Briefly reaching the surface only to be forced to descend back into the facility by mortar fire, Freeman is then tasked by a scientist with tracking down the science team taking shelter in the Lambda Complex on the opposite end of the base, as they may be the only ones who can end the catastrophe.
• Meanwhile, having reached the Freight Yard on the surface, Barney Calhoun has his first encounter with the HECU. In the Freight Management Offices he comes across a dying Harold, who advises Calhoun to rescue Rosenberg, since been captured by the HECU, and has a plan to escape the facility by use of an old prototype of the Lambda Complex's teleporter.
• Keller hatches a plan to create a resonance reversal using the prototype displacement beacon in the Gamma Labs. However, he needs a satellite in orbit before the plan can go through. Personnel in Sector E's High Altitude Launch Center are ready to launch the satellite, but due to a military air traffic lockdown that is in effect they can not. To remove the lockdown, Keller, Cross, and Green travel via the Black Mesa Transit System to the Level 3 Dormitories in search of a security guard with the all-clear codes needed. Here, they have their first encounter with the HECU. Guard found, the group travels to the Black Mesa Air Control facility.
• With the transit system in his location out of action, Freeman is forced to travel through a decommissioned rail system to Sector D's Experimental Propulsion Laboratory, where he destroys three large tentacles sprouting from the base of the silo's tunnel system by firing the rocket engine used in testing.
• Cross and Green fight through several squads of HECU marines and an Osprey and manage to secure Black Mesa Air Control. There they proceed to enter the all-clear codes, lifting the military air-traffic lockdown, and make their way back to Keller to find a way to reach the Gamma Labs.
• Freeman navigates his way through Sector D's tunnel systems and finds himself falling right into a firefight between the HECU and a Gargantua in Sector E's Track Control. Restoring power to the rail system and destroying the Gargantua in the process, Freeman begins his journey through the sector's Materials Transport lines.

• 

  Anti-mass spectrometer dampening lock being reset.

• 

  Facility now under military command.

• 

  M1A1 Abrams tank in the Freight Yards.

• 

  HECU marines in the Level 3 Dormitories.

• 

  Giant tentacles in rocket test silo.

• 

  Osprey at Black Mesa Air Control.

• 

  Battle between HECU and Gargantua.

Night

• Barney Calhoun and Rosenberg make their way to the abandoned Section A-17 Prototype Labs, where a disused teleportation system is being reassembled by doctors Simmons and Walter Bennet. In order for the teleporter to operate accurately, Calhoun is forced to travel to a ruined Black Mesa research camp on Xen and activate a focuser.
• As Gordon Freeman rides the monorail through the Materials Transport system, he's told by a security guard that he must head up to the High Altitude Launch Center to launch the satellite the Lambda Team can use to reverse the effects of the Resonance Cascade. Now actively being hunted by the HECU, Freeman makes his way back up to the surface and to the launch site. He succeeds in launching the rocket into orbit, but is once again forced to travel back underground.
• Gina Cross, Colette Green, and Richard Keller head to the Gamma Labs on the surface to raise the prototype displacement beacon for activation. Keller is able to reach the main lab, but cannot raise the beacon remotely because of an obstruction. Accessing the lower levels of the labs via the drainage canals, Cross and Green reach the beacon, clear the obstruction blocking it from ascending, and raise it successfully.
• Cross and Green return to Keller in the lab control area, where he gives them the task of activating the beam matrix system that provides the power required for the displacement beacon. After navigating through the Alien Quarantine Labs, they reach the beam matrix and attempt to activate it while simultaneously defending it from alien slaves and grunts rapidly teleporting in. The beam matrix is activated, and the two doctors return to Keller, who makes final preparations for the resonance reversal.
• Cross and Green are forced to defend the displacement beacon against the attacking Xen forces, including an alien craft. In the midst of the battle, both of them are caught in a harmonic reflux. Cross and Green return safely and Keller congratulates them on their success.
• The Black Mesa Hazard Course decathlon was to commence at 19:00 PM in the Level 3 Facility, but this never occurs because of the Resonance Cascade.

• 

  Simmons and Bennet reassembling old teleport system.

• 

  Focuser on Xen.

• 

  Entrance to Materials Transport monorail system.

• 

  Satellite delivery rocket launched by Freeman.

• 

  Alien grunt contained within Alien Quarantine Labs.

• 

  Activated displacement beacon.

May 17

• Drone Subjects X-8973 and R-4913 are teleported by their leader into Black Mesa to retrieve a crate of Xen crystals which were stolen and used in tests at the facility. They successfully manage to retrieve the crystals from a Black Mesa Research Facility Transport Division vehicle in the Ordinance Storage Facility's parking garage, which had been intercepted by the HECU.

• 

  Xen crystals in the back of the truck.

Morning

• After it is discovered that the teleporter had used its entire supply of batteries to transport him to and from Xen, Barney Calhoun is forced to go down to a power facility and reactivate the generators required to recharge the batteries.
• Finally nearing escape, Calhoun helps operate the simpler parts of the teleporter to get the three scientists safely on the other side of the portal. Once the scientists escape, the HECU storms the room as he finally teleports himself to the scientists.
• Meanwhile, after encountering an ichthyosaur while searching for an alternate route to the surface, Gordon Freeman reaches a large storage area where he is attacked by Black Ops assassins. After fighting them off, Freeman is hit unconscious by a couple of soldiers. They seize his weapons, and, instead of taking him topside for questioning, drag him to a trash compactor, leaving him for death.
• Calhoun is teleported to the Black Mesa South Access Tunnel but is caught in a harmonic reflux and is teleported to several locations, including a storage room where he witnesses Freeman being carried off towards a trash compactor. Calhoun finally teleports back to the scientists, no longer caught in the harmonic reflux. Together, the group manage to successfully escape the facility in a Black Mesa SUV.
• Freeman wakes up and manages to escape from the trash compactor. He stumbles across the now mostly abandoned Biological Waste Processing Plant, making his way through various hazardous machinery before eventually breaking into the Advanced Biological Research Lab.

• 

  Power generators being reactivated.

• 

  Rosenberg escaping the facility.

• 

  Ichthyosaur lurking in a flooded section of Black Mesa.

• 

  Storage complex where Freeman is ambushed.

• 

  Calhoun witnessing Freeman dragged away by soldiers.

• 

  Calhoun and team make their way to safety.

• 

  Inside Biological Waste Processing Plant.

Afternoon

• Gordon Freeman rearms himself against the HECU and various Xen creatures running amok in the Advanced Biological Research Lab, searching for a group of scientists with scanner access hiding in the lab who can open the front door.
• Meanwhile, Adrian Shephard regains consciousness in the Black Mesa Medical Lab, saved by scientists unaware of the HECU's mission. He is sent to the crash site of his squad's Osprey to radio for help, where he is told that they are pulling out and he must make his way through the underground transit system to reach the extraction point on the surface.
• Freeman again reaches the surface, now a battleground between the US Military and Xen's forces, the latter turning the tide of conflict in their favor. After scaling the Hydro-Electric Dam, the cliff face of the mesa itself, and the battle-torn Topside Motorpool, he overhears a radio message revealing that the HECU are pulling out and abandoning the base, calling in airstrikes to cover their retreat. Freeman uses a tactical map set up by the military in Waste Processing Area 3 to call in airstrikes to open the blocked underground entrance to the Lambda Complex.
• Concurrently, Shephard reaches the extraction point, hearing the same radio message from the source, by whom he is informed of the HECU's evacuation from the facility. Before he can escape, Shephard is deliberately blocked off by the G-Man closing the hangar door as the last Osprey leaves.
• Freeman fights his way through scores of aliens and the remaining HECU forces in the Lambda Bunker of Sector F before finally reaching the entrance to the Lambda Complex proper.
• Shephard searches for an alternate escape route through several blast furnaces, garages, and offices, meeting up with fellow marines who have also been left behind. By now, Race X have begun their full-scale invasion of Black Mesa, intending to set up Gene Worms to assimilate Earth's natural resources.
• On their way to an underground rail system, Shephard's group are attacked by Black Ops, discovering they have been sent to the facility to execute the remaining science personnel and HECU marines after their failed cover-up of the Black Mesa Incident.
• Freeman reaches the Lambda Complex, forced to flood the reactor core in order to access what is left of the science team, where they inform him he must travel to Xen to kill an immensely powerful being keeping the rift between worlds open.
• Separated from his comrades, Shephard finds himself in the Lambda Complex, witnessing Freeman teleport to Xen. After taking a different portal to the alien borderworld, Shephard acquires the Displacer Cannon, teleporting himself into Black Mesa's Hydrofauna Studies Laboratory.
• At 16:30 PM, Otis Laurey was to have his Security Guard training under security officer Miller's holographic assistant counterpart. This never occurs because of the Black Mesa Incident.

• 

  Alien grunt contained within Advanced Biological Research Lab.

• 

  Crash site of Shephard's Osprey.

• 

  AH-64 Apache patrolling Black Mesa cliffside.

• 

  Evacuation of HECU from Black Mesa.

• 

  G-Man preventing Shephard's escape.

• 

  M1A1 Abrams guarding entrance to Lambda Complex.

• 

  Xen-infested blast furnace.

• 

  Black Ops standing guard outside truck loaded with nuclear warhead.

• 

  Shephard witnessing Freeman teleported to Xen.

• 

Evening

• Arriving in Xen, Gordon Freeman encounters its native species in their natural habitats, as well as the remains of several members of the Survey Team that had come before him. Freeman hops his way across the borderworld in search of his target.
• Traversing through the underwater Hydrofauna Studies Laboratory, Adrian Shephard frees a scientist providing him with information on the area. However, Shephard is forced to teleport to Xen and back again, eventually reaching the Black Mesa Biodome Complex.
• Freeman teleports into the lair of the Gonarch, the mother of the headcrabs, and does battle with the creature. After killing it, he continues onwards to the Xen invasion forces' staging grounds.
• Travelling between various biosphere chambers and laboratories in the Biodome Complex, Shephard eventually reaches Waste Processing Area 3, and receives a radio transmission from a group of marines fighting "some sort of worm creature".
• Freeman navigates through a series of mines and factories, in which the alien slaves are tasked with the preparation of alien grunts, before jumping into the portal found at the top of the production line.
• Shephard encounters a Pit Worm nested in the Toxic Disposal Basin of the waste processing area, using the accumulated toxic waste to kill it. Shephard extends a retractable bridge previously blocked by the Pit Worm, and crosses into the sewers leading to the ruined freight hangars of Sector G.

• 

  Xen ecology.

• 

  Scientist cornered by Pit Drones.

• 

  The Gonarch and her brood.

• 

  Specimen habitats in Biodome Complex.

• 

  The factories of Xen.

• 

  Pit Worm in the throes of death.

Dusk

• In the last hours of the Black Mesa Incident, Adrian Shephard makes his way through the underground canals and sewers of Black Mesa, fighting through a Voltigore nest before arriving at the Sector G Topside Hydro Plant. Here, a Gargantua has been trapped on top of the dam and several marines are attempting to kill it. Shephard uses explosives to destroy the creature and leaves the area through the dam's exposed water pipes.
• Shephard enters an underground parking garage, where he discovers that the Black Ops intend to activate a thermonuclear warhead to destroy the facility. Shephard kills the remaining Black Ops squad in the parking lot and deactivates the thermonuclear device, but later sees the mysterious figure from earlier reactivating it.
• Gordon Freeman is teleported into a vast cave in which he finally confronts the powerful and mysterious being holding the portal open, the Nihilanth. In the ensuing battle, Gordon destroys the crystal that allowed the Nihilanth to regenerate its strength, allowing him to attack its vulnerable brain. As the massive being enters its death throes, it floats toward the ceiling and explodes in a giant green blast that overpowers Freeman's senses. The death of the Nihilanth leads to the liberation of the Vortigaunts from their subjugation under its control.
• Freeman is confronted by the G-Man. Both are transported to various locales around Xen while the G-Man praises Gordon's actions there. He explains that his "employers" are now in control of the borderworld for the time being and have authorized him to offer Freeman a "job", agreeing that he has "limitless potential". The final teleportation places them inside a tram identical to the one Gordon rode on the morning of May 16 that is flying through space at immense speed. Gordon accepts the G-Man's offer by stepping through a portal and hears the G-Man's voice one last time: "Wisely done, Mr. Freeman, I will see you up ahead." The G-Man hires him and places him in stasis for nearly 20 years.
• After making his way through warehouses filled with Race X creatures and Black Ops fighting, Shephard arrives at an old industrial area of Black Mesa where an enormous Gene Worm is attempting to come through an interdimensional rift to the Race X homeworld. Shephard uses mounted laser weapons to blind and kill it before it can fully emerge; in its death throes, an enormous portal spreads outwards and envelops him.
• Shephard regains consciousness inside an Osprey Heliplane, confronted by the G-Man. As the G-Man talks to Adrian, a white flash occurs in the distance as Black Mesa is destroyed by the thermonuclear bomb. The G-Man then informs Shephard that he will be detained "in a place where you can do no possible harm, and where no harm can come to you." He explains this is done since Adrian reminds him of himself, but is still a dangerous witness. The G-Man walks into a portal as Shephard is detained.
• Following the destruction of the Black Mesa Research Facility, GLaDOS' race against Black Mesa is concluded.

• 

  The Gargantua trapped on top of the Hydro-Electric Dam.

• 

  Black Ops soldiers preparing the bomb.

• 

  The Nihilanth standing before Freeman in its chamber.

• 

  The Nihilanth as it is defeated by Freeman.

• 

  Gary's mural depicting the death of the Nihilanth and the Alien Controllers.

• 

  Gary's mural depicting the liberation of the Vortigaunts.

• 

  The G-Man offering Freeman a "job".

• 

  The Gene Worm entering Black Mesa through a massive portal.

• 

  The G-Man talking to Shephard in the Osprey as Shephard is detained.

May 18

• At 8:00 AM, Colette Green was to conduct a Public Relations Tour. This never occurs because of the Black Mesa Incident.

• 

Combine Invasion of Earth

• Portal Storms rage on Earth while Xen creatures continue to be teleported to random locations. Attempts to explain the storms vary, with explanations ranging from the meteorological consequences of climate change to clandestine scientific experiments. Governments' abilities to protect their citizens are stretched to the breaking point as government food banks set up in recent days quickly begin to suffer from crippling demand.
• The Aperture Science Enrichment Center remains in lockdown, with employees still trapped inside. The number of Aperture Science employees diminishes, until there are only a few left. The last surviving employee, a schizophrenic programmer named Doug Rattmann, manages to avoid captivity as a result of his paranoia. Evading GLaDOS' constant attempts to capture him, he manages to gain access to her Test Subject personnel files and research the psychological profiles of rejected candidates, including Chell, who was rejected for testing due to her extraordinary tenacity. Hoping Chell's stubborn determination might allow her to defeat GLaDOS, Rattmann tampers with the Test Subject roster, rearranging the order so that Chell's name is at the top. This seems to go unnoticed by GLaDOS. From this point on, Rattmann hides in unused portions of the facility, where GLaDOS is unable to monitor him. She then resumes mandatory testing.
• The Combine launches an assault on Earth. In the Seven Hour War, Earth military forces resist despite being clearly outmatched by the Combine's resources and technology. Untold humans lives are claimed by the assault in mere hours as cities are torn apart by Combine Synth forces and projectiles launched by from outside Earth's atmosphere. Dr. Wallace Breen, the administrator of the Black Mesa Research Facility, contacts the United Nations claiming that he has determined how to communicate with the Combine and is given complete freedom to negotiate for peace at all cost. On Breen's orders, on behalf of hundreds of national governments, the United Nations cedes the entirety of planet Earth, with all its states and peoples, to the Combine. Breen is appointed as Earth's Administrator, responsible for controlling the population under Combine rule. The events prompt speculation that the Portal Storms of recent days may have been intentional prelude to an attack. There is little consensus on any of the unprecedented events, but some prominent biologists and zoologists believe the Combine to be a species distinct from the lethally aggressive "portal creatures".
• Portal Storms continue as millions are left in desperate need of food and shelter as existing food supplies sit idle, unable to reach their destinations due to disrupted supply lines and a lack of coordination. Experts warn that preventable deaths will occur if the situation continues. Psychologists and disaster response experts advise members of the public to remain in their homes and avoid falling prey to panic. Federal emergency response officials encourage citizens to rely on their own existing food and water stockpiles before making use of government food banks. Militaries, U.N. peacekeeping forces, and volunteer militias are stretched to their breaking point as the storms rage on. Musical superstars join forces to celebrate the lives of the fallen and issue a call for interplanetary peace and cooperation with the "EarthAid Unite" concert broadcast on the weekend.
• Scientists remain unable to offer any solution to the ongoing portal storms devastating cities worldwide, nor are they any closer to determining how to predict when new portals will appear. Contrary to early speculation, however, there is a growing consensus that the storms have not been instigated by the Combine forces; experts note that the "portal creatures" and the Combine appear to be adversaries, and that "our planet may be little more than a battleground for two enemy species that have little regard for humanity."
• Stock values plunge in the wake of the Combine's assault on Earth, with most major markets having now closed until further notice. Markets in New York, Shanghai, Hong Kong, London and continental Europe have suspended trading. Communication lines out of Japan are largely inactive, leaving the status of Tokyo's stock market currently unknown, but assumed to be closed. The Securities and Exchange Commission says that it does not expect trading to resume in the United States for the foreseeable future, given the extreme global uncertainty and instability.
• Breen faces criticism for his role in humanity's surrender, with critics accusing him of rank opportunism, simply "selling out humanity after simply being in the right place at the right time" and "essentially legitimizing an interplanetary coup." Other critics point out that since no concessions were extracted in the negotiations with the Combine, humanity has no leverage over them whatsoever, allowing the Combine to make as many further demands as they wish. Breen argues that he took the only possible course of action given the extreme nature of the situation, and that "those who know me and my work know that I'm not a politician. I'm a scientist." Some remain sympathetic to Breen, however, arguing that any ability to communicate with the Combine outweighed issues of governance.

• 

  Newsclips of this period seen in Black Mesa East.

• 

  A Portal Storm in the Outlands, 202-.

• 

  Doug Rattman placing Chell at the top of the Test Subject roster.

• 

  Front page of The Times newspaper on the day following the Seven Hour War.

• 

  Front page of The Terminal newspaper after the Seven Hour War.

• 

  Front page of the 7 days newspaper after the Seven Hour War.

• 

  Restored newspaper clipping displaying damaged caused to the United Nations Secretariat Building in New York City during the Seven Hour War.

• 

  Breen featured on the cover of Tech Impact magazine, 200-.

Between 200- and 202-

• Earth's ecosystems are contaminated by alien fauna, flora and radiation. The Combine activates a field that suppresses human reproduction and introduces a chemical into the water supply that causes forgetfulness. The remaining human population are relocated to numbered cities devoid of their original names, where they are systematically suppressed to prevent any interference with the Combine's overarching objectives. Human soldiers are assimilated into the Combine Overwatch, the humanoid police and military forces stationed on Earth that are primarily responsible for subjugating humanity under Combine rule. The forces of the Overwatch are assigned to distinct "sectors" designated around an urban center, and are overseen by the Overwatch Voice which acts as their immediate commander, issuing them orders and instructions to fulfill objectives on the field. Branches of the Overwatch include Civil Protection, the Transhuman forces, the Synths and Airwatch.
• Surviving Black Mesa scientists, including Isaac Kleiner, Eli Vance and Arne Magnusson, continue to research inter-dimensional technology with the hope of freeing Earth from the Combine's rule. Kleiner and Dr. Vance relocate to City 17, where Dr. Vance contributes in founding the local Resistance movement, and becomes the leader of Black Mesa East. During his work at Black Mesa East, while working with Kleiner and Judith Mossman on teleportation, Dr. Vance designs the Zero Point Energy Field Manipulator and rebuilds a Scout Car with his daughter for the Resistance outposts located along the Coast, on which he mounts a Tau Cannon. During this period, he also loses his left leg to a Bullsquid while helping Kleiner climb over a barrier to get into City 17.
• Dr. Vance becomes the first human being to make peaceful contact with the Vortigaunts, quickly persuading the alien race to ally with humanity against the Combine. The Vortigaunts later state that Dr. Vance earned their trust, is indispensable to the liberation and that he almost perceives the "All-in-One".
• Alyx Vance grows up under Combine rule, living in and around the new Earth capital, City 17. Dr. Vance builds Dog to protect her. As she reaches adulthood, she begins working with the Resistance. As one of the core members of the City 17 branch, her contributions mostly include assisting Kleiner and Barney Calhoun in helping Citizens escape the city to Black Mesa East through the old canals, as well as helping Kleiner, her father and Mossman establish a teleport connection between Black Mesa East and Kleiner's Lab.
• Ravenholm, a former coastal mining town in the Wasteland, is discovered and occupied by Resistance members and refugees fleeing from City 17 who hope to join the Resistance. One of these refugees is Father Grigori, who becomes the pastor of the town's church. The town remains under the radar for some time until it is eventually discovered by the Combine, leading to a massive Headcrab Shell bombardment that releases tons of Headcrabs, completely overrunning the town and turning most of its population into Zombies. Being linked to Black Mesa East via a tunnel, the entrance to Ravenholm is sealed shortly after the shelling using a heavy gate, two barricades of crates, and stolen Sentry Guns to prevent Zombies from escaping. As the only survivor of the shelling, Grigori descends into madness, deciding to remain in the town and constructing a variety of deadly traps so that he can liberate his 'congregation' from their zombified states through death.
• The Resistance's new teleporter is tested on a cat, but the experiment is a failure, resulting in an unknown fate for the animal that would traumatise Calhoun for years to come. They then continue working on the device until Freeman's arrival.

• 

  An early Polaroid photo of Dog kept by Alyx Vance.

• 

  Alyx's marked globe following the Combine's rule as seen in her hideout.

• 

  Xen infestation in the City 17 Quarantine Zone.

• 

  Civil Protection officers conducting a sweep of a city street.

• 

  A Headcrab Shell near the Ravenholm cemetery.

2010s

2010

• A short amount of time after the Combine invasion of Earth, somewhere around the year 2010, in the Aperture Science computer-aided Enrichment Center, Chell is awoken by GLaDOS who forces her perform seemingly routine tests. However, Chell soon learns that the Aperture employees are long dead or escaped, and that GLaDOS is seemingly the only being left in the decaying facility. After much promise of cake at the test's conclusion, Chell is met with an incinerator, which she narrowly escapes, and works her way through the maintenance areas, despite GLaDOS' protests. Eventually, Chell finds GLaDOS' control room, and manages to escape death by neurotoxin by detaching GLaDOS' Personality Cores, and partially destroying her as a result. Chell is forced to the surface by GLaDOS' explosion, only to be dragged away from freedom and back into the facility by the Party Escort Bot. Unknown to Chell however, GLaDOS is still alive.
• Doug Rattmann, the last Aperture employee alive, witnesses GLaDOS' destruction. After the Party Escort Bot drags Chell back into the facility, Rattmann feels guilty for Chell's situation and reenters the facility to help her. At the beginning of her stasis, Chell is under Rattman's supervision.
• GLaDOS' partial destruction is followed by a period of inactivity within the Enrichment Center, during which time maintenance systems and Personality Cores maintain its functions. The facility remains in disarray, having become overgrown and dilapidated. Pre-recorded 'Emergency Test Protocols' can oversee test chambers in times of cataclysmic system failure, "remain[ing] functional in apocalyptic, low power environments of as few as 1.1 volts. Chell spends this time in stasis for over 50 millennia.
• Despite all that's occurred to both the outside world and the Aperture Science Enrichment Centre, the company receives a purchase order on the 25th of January for a blue sentry turret from a T. Reidford. The order will not begin preparation for roughly 50,000 years.

• 

  GLaDOS' remains on the Aperture Laboratories parking lot shortly before Chell is dragged away by the Party Escort Bot.

• 

  Rattmann seeing Chell being dragged away by the bot.

• 

  A Sentry Turret box.

Fifty days later

• Fifty days after she was put back in stasis, Chell is awakened within an Extended Relaxation Chamber by an unidentified announcer. In compliance with "state and federal regulations," Chell is instructed to perform a mandatory physical and mental wellness exercise. She is then instructed to return to bed, where she will remain in stasis for roughly 50,000 years.

• 

  Inside of Chell's Relaxation Chamber.

Between 2010 and 2019

• Arne Magnusson begins work on the White Forest satellite delivery rocket.

• 

  The White Forest rocket.

Between 2015 and 2024

April

• By now, the Citadel has begun construction. As described in Alyx's observations, the initial spire structure appears from the center of a deep crater in the ground, and a perpetual storm rages above the structure.

• 

  Alyx Vance's monitoring of the Citadel's construction.

June

• Some sort of scaffold and feeder cables appear around the main structure of the Citadel. A perimeter wall is built surrounding the crater at the bottom of the structure, and a "flight deck" and oscillating "ribs" appear near the top of the tower. The storm above seems less aggressive, but the top of the tower is still shrouded by clouds. The purpose of the Citadel remains unknown.

July 19

• An unidentified green jar in Alyx's Hideout is dated to this day.

• 

November 29

• Alyx details her most recent observations of the Citadel's construction. She observes lights coming from the tower as some sort of power source appears in the center - this "mini reactor" appears to be inconsistent and self-contained, often causing blackouts. It seems to draw power from the Citadel's new power source. The scaffolds around the tower appear to be mobile. More cables appear daily.

• 

  The Citadel at the beginning of Half-Life: Alyx.

On or After November 29

Morning

• 19-year-old Alyx Vance is reconnoitering on the Citadel's construction process as she receives a call from her father Eli Vance and the Resistance member Russell, who are stealing a mini-reactor from the Combine. She reports to Dr. Vance that everything is normal, albeit she has noticed troops moving supplies into the Quarantine Zone. Just then, Dr. Vance catches sight of a strange floating structure, which triggers a massive manhunt that results in the capture of both Alyx and Dr. Vance. Russell manages to rescue Alyx while she is being held captive in prisoner transport vehicle, and he leads her to his lab with the help of his drone and warns her that the Combine will transport Dr. Vance to Nova Prospekt for interrogation. He formulates a plan for Alyx to intercept the train carrying Dr. Vance at Fairview Junction. Alyx is given a gun and a pair of Gravity Gloves, and she then embarks on a journey to save her father.
• The train Alyx gets on eventually stops outside the cordoned off Quarantine Zone, and she is forced to venture further on foot to reach Fairview Junction, combating vicious Xen wildlife along the way. In a concealed abode, she meets an eccentric Vortigaunt living in solitude named Gary, who explains that the Combine performed a procedure on his brain that severed him from the Vortessence, and as a consequence he is “alone in his head”. He makes vague allusions about Dr. Vance suffering an untimely death in the future, and alleges that Alyx cannot change this fate by herself. He asks her to help free his imprisoned kin, who are being used as biological batteries to keep the vault structure afloat, and also instructs her to "look to the Northern Star". Despite not understanding his admonishments, Alyx thanks Gary and bids him farewell.
• After making her way through the Drainage Tunnels, Alyx finally arrives at Fairview Junction. She battles the Combine forces there and manages to derail the Razor Train carrying her father, killing at least three Combine Advisors inside. She enters the train wrecks to discover Dr. Vance hanging over an abyss, and Gary arrives just in time to rescue him from a fatal fall. Dr. Vance warns Alyx that, while in custody, he learned that the Combine is apparently storing a "superweapon" in the floating Vault, and prompts her to find and infiltrate the Vault and steal the weapon before it can be relocated. Gary repeatedly instructs Alyx to “look to the Northern Star”. While she initially believes that his words are simply another example of Vortigaunts speaking in riddles, it is later proven that he was talking in a literal sense in this case.

• 

  Russell using a holographic map in his lab to explain his plan to rescue Dr Vance.

• 

  Entrance to the City 17 Quarantine Zone.

• 

  A squad of Combine Grunts caught by Barnacles in the Drainage Tunnels.

Afternoon

• Gary promises to escort Eli Vance back safely, and Alyx Vance continues to navigate through The Terminal Gardens Metro Station. In an office building above the station, she sees the Vault for the first time and realizes that multiple substations linked to it via cables need to be subdued in order to bring it down. On her way, a Combine squad tracks her down and tries to impede her mission, identifying her as "seismic activity". After defeating the Combine troops, she emerges from the underground station and discovers that the Northern Star is actually a real hotel located across a plaza, and is the place where one of the generator substations supporting the Vault is located.
• Alyx enters the Northern Star hotel and makes her way to its rooftop, navigating through overgrown rooms full of Xen flora as she moves towards the substation. In the hotel, she discovers "lightning dogs", Headcrab-like creatures that can generate electricity and possess host bodies. Her journey in the hotel is obstructed, and so she ventures down to its basements and traverses through its stories before getting to the substation. Eventually, Alyx manages to destroy the cables connected to the Vault and disable the substation. She discovers that each substation contains an enslaved Vortigaunt which is forced to channel its electrical energy to the Vault to power it. Grateful for its freedom, the liberated Vortigaunt promises Alyx to rally its peers to take down the remaining substations. Although Russell voices his disbelief for the Vortigaunts' abilities, Alyx trusts them as their only allies. She then leaves the hotel and proceeds towards the Vault, fighting more Combine troops who are now actively pursuing her.

• 

  Entrance to the Terminal Gardens metro station.

• 

  Exterior of the Northern Star hotel with a Combine substation attached to it.

Dusk

• Alyx Vance enters the Holden Company Processing Plant and makes her way through its Zombie-infested rooms. On the way, Russell and she witnesses the Vortigaunts taking down another substation, much to their delight. In the facility, she makes her first encounter with Combine Suppressors and successfully gets past a room filled with tripmines and explosives, blocking the entry to the abandoned Golden Lion Distillery. She fights more intercepting Combine soldiers before finally entering the Distillery, hoping to find a route to get across to the Vault indirectly.
• Inside the distillery, she meets a human survivor, Larry, who appears to be stranded with a monstrously mutated Combine Hazmat Worker nicknamed Jeff. Jeff was deformed due to sustained exposure to infectious spores, which turned him into a bizarre and violent creature that is blind but extremely sensitive to sound. Alyx finds a Combine seal that needs to be lifted in order to proceed, and she carefully maneuvers her way around the distillery looking for three batteries to power the seal while avoiding Jeff, ultimately tricking him into a trash compactor. After opening the seal, she then heads down into the tunnel underneath, discovering evidence of dangerous Antlions present in the area.

• 

  Vortigaunts successfully taking down another substation.

• 

  Alyx's first encounter with Jeff, who is roaming the distillery.

Night

• Alyx Vance finds herself in an abandoned zoo filled with Antlions. While she fights her way through the Antlion swarms and the Combine soldiers, Eli Vance gets into contact with her and warns her that the Vault isn't storing a weapon, but is in fact a prison containing something or someone that even the Combine fears. The Vault itself appears to have been constructed around an entire apartment building torn from the ground in order to contain whatever or whoever is inside it, and was then made to levitate in the sky in the Quarantine Zone as an extreme containment measure. Alyx continues, reasoning with her father that whatever or whoever is inside the Vault dislikes the Combine too, and can help them fight against it, so she makes up her mind to retrieve it.
• After the deactivation of the last Combine substation, the entire Vault structure begins to crash into the ground. However, a backup device mounted on a water tower is triggered to emit a field that raises the Vault and prevents it from falling. Alyx immediately begins to head toward the backup device. After battling through a swarm of Antlions and Overwatch soldiers, she notices a mysterious silhouette through the window of a building. Upon entering, Alyx overhears the unidentified woman, known as "The Scientist", expressing her frustration at a Combine Advisor on a screen for not being able to keep the Vault sufficiently guarded, and urging the Advisor to move the Vault away as quickly as possible before Alyx can get to it. During the conversation, Alyx hears the woman mentioning that the Vault contains a survivor of the Black Mesa Incident who wreaked havoc and "then disappeared". Eli deduces that the woman must be referring to Gordon Freeman, and tells Alyx it is of utmost importance that he is freed.
• Alyx fights her way through the Combine enemies and finally arrives at the backup station. She tries to dock the Vault to the station, but cannot find the correct lever combination to do so, in the end accidentally causing the Vault to come crashing down. Alyx awakens in debris caused by the Vault's collapse and ventures down into a destroyed parking garage. In the garage, she finds numerous shocked Combine Grunts reporting damage status to the Overwatch Voice and a few incapacitated Striders lying about. After Alyx deals with the soldiers and restores power to a nearby elevator, the formerly deactivated Strider regains consciousness and begins firing at her, forcing Alyx to flee through the debris of various destroyed buildings while simultaneously battling reinforcing squads of soldiers. Eventually, Alyx finds a Combine Mounted Gun installed on a Combine Prisoner Transport and uses it to defeat the Strider. After finally disposing of all enemies, Alyx leaps into a green beam that appears to be pulling objects into the Vault. Russell wishes Alyx good luck as she ascends into the Vault just before Dr. Vance interjects with a warning that is cut-off by radio interference, leaving Alyx alone floating into the mysterious Vault with her weapons lost.
• Boarding the Vault, Alyx finds herself in the abandoned apartment complex which the Vault was built around, suspended in a highly surreal state: bedrooms, kitchens, and living rooms are superimposed on top of one another and people living within the complex are seemingly trapped in a certain point in time, constantly fading into and out of existence. Indescribable physical phenomena permeate the entire building, apparently under the influence of some powerful spacetime disturbance, rendering its environment bizarre and unpredictable. Alyx navigates through the paranormal contents of the Vault, battling the last bastion of Combine Overwatch soldiers stationed there using the Vortigaunt energy her gloves absorbed. After defeating the soldiers, she crosses a narrow energy bridge to discover a strange icosahedral prison cell in the center of the Vault which she then breaks open. However, instead of finding Gordon Freeman, she releases the G-Man. The G-Man makes an offer to Alyx, showing her a vision of the future where her father is killed by a Combine Advisor. The G-Man allows Alyx to intervene, saving Eli and killing the Advisor, but it comes at the cost of her freedom as she's then "hired" by the G-Man and put into stasis against her will.

• 

  Sentry Guns firing on an Antlion at the entrance to the Central Zoo.

• 

  Alyx observing the Scientist speaking to a Combine Advisor.

• 

  Alyx using a mounted gun against the Strider.

• 

  The exterior of the icosahedral cell of the Vault.

• 

  The G-Man making an offer to Alyx.

Between 2019 and 2028

• This is the last time Alyx Vance drives Highway 17.

Summer

• Alyx leaves the Scout Car with Leon at Shorepoint Base.

• 

  Shorepoint, with the Scout Car on Pier 87.

2020s

Between Autumn 2020 and 2029

Day 1 of Freeman's return

• Approximately two decades post the Black Mesa Incident, sometime in autumn, the G-Man rouses Gordon Freeman from stasis, inserting him into a train bound for City 17. Upon reaching the station, Freeman disembarks into a world now dominated by the Combine. Upon being stopped at a checkpoint, Freeman is subsequently directed into a compact interrogation room where he encounters Barney Calhoun, who is now operating incognito as a Civil Protection officer. Initiating contact with Isaac Kleiner, the trio strategizes, ultimately deciding to guide Freeman to Kleiner's Lab. However, due to Calhoun's need to maintain cover, Freeman is forced to independently navigate the perilous journey. Negotiating through apartment complexes, Freeman unwittingly becomes embroiled in a Civil Protection raid, narrowly escaping peril and, fortuitously, being rescued by Alyx Vance.
• Freeman finds his way to Kleiner's lab with Alyx's help, with Alyx revealing to him information about the state of the world and Wallace Breen. Alyx explains her part in the underground Resistance network, which has been helping people escape the city on foot. At Kleiner's lab, it is decided that Freeman and Alyx should be teleported to Black Mesa East. After meeting Kleiner's pet headcrab Lamarr, Freeman receives the Mark V HEV Suit. Alyx is teleported to Black Mesa East successfully. When trying to teleport Freeman, however, Lamarr leaps onto him, causing the machine to malfunction and teleport him to various random places, including the Wasteland, twice at Black Mesa East, the middle of the ocean (where he is almost eaten by an Ichthyosaur), and Breen's office in the Citadel. Breen is startled by Freeman's sudden re-appearance, and subsequently places the Citadel on high alert. Finally ending up outside the lab where he started, Freeman is forced to head on foot to Black Mesa East by himself. Before he leaves, Calhoun gives him a crowbar which he apparently left at Black Mesa, telling him that he needs to travel through the extensive canal system of City 17 to reach his destination. Thousands of Overwatch units are deployed across City 17 in an effort to to crack down on and destroy all known resistance bases in Freeman's path in an attempt to halt him.
• Freeman travels through the underground railroad, where he discovers the network of resistance bases located along the canals established to help refugees escape. Freeman is chased by the Combine through the railroad, and the few resistance shelters he finds are quickly raided by Civil Protection, either being shelled or flooded with Manhacks. Gordon acquires a 9mm Pistol and engages in combat with Civil Protection forces and Xen fauna before arriving at Station 6, where he acquires an airboat.
• Aboard the airboat, Freeman is pursued through the Canals by hundreds of Civil Protection units and several Hunter-Choppers. Along the way, he stops at several Civil Protection outposts along the Canals, where he learns that he has become the Combine's number one target. Eventually, after dispatching of a Hunter-Chopper above the dam at Port 5, Freeman reaches his destination, Black Mesa East.
• Freeman meets Judith Mossman for the first time and is reunited with Eli Vance, along with Alyx. Freeman is also introduced to the Gravity Gun, and Dog, Alyx's robotic "pet." Alyx takes Freeman to the scrapyard in order for him to practice with the Gravity Gun. Along the way, they pass by a sealed off tunnel to Ravenholm, of which Alyx speaks fearfully. While Freeman is playing with Dog in the scrapyard, Alyx spots Combine Scanners sweeping the area, shortly before an all-out aerial raid on Black Mesa East. While attempting to rejoin the others, Freeman and Dog are separated from Alyx by a collapsed ceiling, and Freeman is forced to escape down the tunnel to Ravenholm.
• Freeman makes his way through Ravenholm at night, fighting zombies and avoiding bizarre man-made deathtraps. Freeman eventually meets Father Grigori, the sole survivor of the shelling of the town. Grigori gives Freeman a shotgun and guides him through the town. Freeman and Grigori join at the church and make their way to an old mine with a path leading to the coast After battling through the graveyard to the mine entrance, Grigori decides not to leave with Freeman, opting to remain in the town. As Freeman departs, Grigori continues fighting the zombies until he disappears into a fire inside a crypt. Freeman then makes his way into the town's mines.

• 

  The City 17 Trainstation Plaza.

• 

  Alyx teleporting to Black Mesa East.

• 

  The aftermath of the massacre on Station 1.

• 

  A Hunter-Chopper passing by Station 7.

• 

  The front docks of Black Mesa East, concealed by a generating station.

• 

  The courtyard of Ravenholm's entrance.

Day 2 of Freeman's return

• Gordon Freeman exits the Ravenholm mines in the morning, where he first encounters Combine Soldiers and Snipers on the abandoned railway tracks. After fighting alongside Resistance fighters in a shootout against a squad of soldiers, Freeman is informed by Alyx Vance via radio that Eli Vance has been captured and taken to Nova Prospekt, and so Freeman sets out on a journey along Highway 17 to rescue him, making use of the resistance's Scout Car, which he uses to safely travel along Highway 17 and the coastline. He is warned to be cautious on his journey, however, as it is currently spawning season for Antlions.
• Freeman travels along the coast, stopping by at several abandoned outposts containing supply caches while evading swarms of Antlions. After a short time of driving, he reaches New Little Odessa, where he meets Colonel Odessa Cubbage and helps fend off a Combine Gunship with a laser-guided RPG. Freeman then arrives at Dock 137, where he clears the facility of Combine Soldiers and continues down the highway, only to be attacked by another Combine Gunship that has been radioed in. Overcoming the hazard, Freeman reaches Bridge Point, where, after disabling force fields, he crosses the rail bridge with his Scout Car, and then arrives at Lighthouse Point.
• At Lighthouse Point, Freeman helps the Rebels hold off several squads of Combine Soldiers offloaded by Combine Dropships and takes down a Combine Gunship from the top of the lighthouse. Then, being led to a secret exit, he proceeds through a cliff path. After carefully avoiding disturbing the Antlions buried beneath the sand, Freeman comes across the Vortigaunt Camp, where he faces an Antlion Guard. After coming out victorious, an ally Vortigaunt Shepherd extracts pheropods from the body. He is led by the Vortigaunt Shepherd through the base and into a cave, in which he is taught how to use pheropods to tame and command the Antlions. Upon completion of training, Freeman is led out onto a beach that connects to Nova Prospekt. Freeman fights his way along the beach, leading groups of Antlions and battling his way through Nova Prospekt guards set up in bunkers on his way into the prison.
• Freeman breaches Nova Prospekt's defenses, fighting his way through an intense assault while making steady progress towards the facility's train depot. When he arrives at the depot, he intercepts a prerecorded message from Wallace Breen, who expresses his frustration and displeasure with the transhuman forces for their failure to capture Gordon, berating them for their incompetence.
• Freeman rendezvous with Alyx Vance at the Nova Prospekt train depot. They search the facility for both Dr. Vance and Judith Mossman, after discovering that she has been collaborating with the Combine. Freeman and Alyx temporarily split up, but are reunited to track down Mossman. Alyx hatches a plan to use the Combine teleporter to transport themselves, along with Dr. Vance and Mossman, to safety at Kleiner's Lab. However, in a critical moment, Mossman seizes the opportunity to escape with Eli to the Citadel. Facing imminent danger from the advancing Combine forces, Freeman valiantly defends their position, providing the chance for Alyx and himself to escape through the teleporter. Due to a slow teleport sequence, it will take them over a week to return to Kleiner's Lab.
• The destruction of Nova Prospekt and the Combine's only teleport prompts the Resistance to launch an uprising against the Combine in City 17.

• 

  The dry seabed at Dock 137.

• 

  Combine Bunkers overseeing the beach below Nova Prospekt.

• 

  The Nova Prospekt compound.

• 

  The Combine teleport in the lower levels of the Depot.

• 

  Heavily damaged street during the Battle of City 17.

"Over a week" later

• Upon arriving in Kleiner's Lab after teleporting away from the depot, Gordon Freeman and Alyx Vance discover they had been stuck in a slow teleport for over a week's time. Freeman goes on to help Resistance fighters in the uprising, while Alyx remains in the lab to help Isaac Kleiner escape the city. Later, Alyx returns to help Freeman but is captured by Combine soldiers and taken to the Citadel.
• Freeman teams up with Barney Calhoun, together leading a battle at the Overwatch Nexus and disabling a generator powering a suppression device that is hampering resistance attacks, eventually fighting their way to the foot of the Citadel. There, they encounter Dog, who provides a pathway into the Citadel by lifting up a portion of a Combine Smart Barrier, allowing Freeman to pass through.
• After making his way into the Citadel through use of a Stalker pod, Freeman is caught in a Combine weapon confiscation field. This destroys most of his weapons except for the Gravity Gun, instead causing the field to malfunction and overcharge it. Freeman fights his way through the Citadel against large numbers of Combine soldiers as Wallace Breen attempts in increasing desperation to convince Freeman to surrender. Freeman is forced to enter another Stalker pod and is quickly discovered on camera, transferring him to the top of the Citadel directly to Breen's office.
• After being transported to Breen's office, Gordon is reunited with Eli Vance and Alyx who are both being held captive as well. Breen tries once again to gain the allegiance of Dr. Vance, but after being refused, he prepares to send Freeman, Alyx, and Dr. Vance through a portal to the Combine Overworld. Mossman protests, but after being brushed off by Breen, decides to intervene, releasing Freeman, Alyx, and Dr. Vance. Breen attempts to escape, fleeing to the Dark Energy Reactor at the very top of the Citadel to be transported himself to the Combine Overworld. Freeman gives chase, arriving at the portal atop the Citadel just before it fully opens. Freeman attacks the reactor using his Dark Energy-infused Gravity Gun, causing the reactor to fail and go critical. Just as the reactor explodes, the G-Man freezes time and addresses Freeman. The G-Man congratulates him on his success, stating that he has received "interesting offers" for Freeman's services. Freeman is put back into stasis, along with Alyx.
• Dr. Vance and Mossman use one of Breen's escape pods to leave the Citadel, later reaching a Vortigaunt camp outside of City 17. Mossman travels north of City 17 with her team to attempt to track down the Borealis.

• 

  Resistance fighters standing guard inside a damaged underground road tunnel.

• 

  Combine Overwatch forces preparing for battle.

• 

  Combine Prisoner Pods being transported within the Citadel.

• 

  The G-Man arriving to place Freeman back into stasis.

A few days later

• Gordon Freeman and Alyx Vance are rescued from atop the Citadel by several Vortigaunts, who remove them both from stasis against the G-Man's wishes. Freeman wakes up outside the Citadel, buried under a pile of rubble. Dog digs Freeman out and he is reunited with Alyx. She contacts her father and Isaac Kleiner to inform them that Freeman is safe. Kleiner tells Alyx that the Citadel Core is at risk of exploding at any moment, so Alyx and Freeman re-enter the Citadel to try to reactivate the stabilization mechanism for the core in order to avert disaster. After a brief encounter with an Advisor, they proceed down a glass elevator to the Citadel Core.
• Freeman and Alyx are successful in re-engaging the reactor's containment system, delaying the explosion. Alyx subsequently discovers that the Combine are trying to use the reaction, and therefore the destruction of the Citadel, to send a message to off-world Combine forces. They receive a transmission from Judith Mossman in the arctic, where she discusses the "Project" which she and her team had discovered, before being cut short as the Combine attacks the base. She is able to run away, presumably to safety, before Combine troops invade the area she had been filming in. Alyx makes a copy of the message packet to take to Kleiner and Dr. Vance, ensuring that the Combine make them their prime target and even in their disorganized state use everything they have to stop them. Alyx and Freeman then board a Razor Train to escape the Citadel, before the train unexpectedly derails. After escaping from the wreckage, the pair fight through the abandoned underground parking garages and tunnels of the city together, searching for a way to the surface.
• Eventually, the pair manages to find the exit of an underground train station and they arrive at the surface. As Alyx and Freeman move on through the ruins of City 17, they eventually reunite with Barney Calhoun and a group of survivors who are preparing to move on a train station in order to escape the city. With the Combine still following, Freeman and Alyx split up from the group and move through a derelict hospital to draw the remaining Combine forces away from the refugees.
• Upon reuniting with Barney at the Technical Trainstation, Alyx and Freeman work to move the Citizens to the trains while facing increasing Combine opposition. They then decide to stay behind to lure the Combine away from Calhoun and the citizens as they board the train and make their escape. After battling Combine soldiers and a Strider, the duo reprogram another train and board the caboose. As the Citadel nears its final moments, the Combine successfully manage to transmit a signal back to the Combine Overworld, requesting assistance to their forces on Earth. City 17 is destroyed during the ensuing explosion as force of the shockwave then hits Alyx and Freeman's train, knocking the pair unconscious.

• 

  The G-Man being halted by the Vortigaunts.

• 

  Alyx contacting her father after finding Freeman beneath the rubble.

• 

  Drop-down view of the Citadel Core.

• 

  Dead Zombines inside a crashed Razor Train.

• 

  A Strider among City 17 rubble.

• 

  The destruction of the Citadel.

The next day

• Gordon Freeman and Alyx Vance emerge from the trainwreck. A superportal has begun forming above the collapsed Citadel. A portal storm occurs, appearing to emanate from the Citadel ruins, destroying the damaged rail bridge and opening a path into a mine shaft for Alyx and Freeman to follow. They travel through an infested mine tunnel to a communication building, and Alyx is able to contact White Forest base to try and deliver their data packet. Shortly afterward, Alyx is critically wounded by a Hunter. A Vortigaunt arrives in time to drive off Antlions and stabilize Alyx's condition. Gordon becomes separated from Alyx and the Vortigaunt and must travel through Antlion caves to meet them at a nearby Resistance outpost.
• Freeman arrives at a small Resistance outpost within the mines manned by Griggs and Sheckley. The Lone Vort has brought Alyx to the outpost and is awaiting the arrival of his kin in order to heal her wounds. Griggs, Sheckley and Freeman are barely able to hold off several Antlion attacks until the Vortigaunts arrive. The Vortigaunts assist in dispatching the next wave of Antlions and proceed to tend to Alyx. The Vortigaunts are unable to save Alyx, however, without the use of an Antlion larval extract, so Freeman and his Vortigaunt companion travel deeper into the mine to retrieve it. Gordon and the Vortigaunt travel deeper into the Antlion caves, encountering the Antlion Guardian, protector of the larval extract. Freeman is forbidden from killing the Guardian for fear of spoiling the extract and hence must outrun the creature through the caves. He is able to avoid the Guardian and summon the Vortigaunt to the Nectarium where the extract is obtained. They deliver the extract just in time, and the Vortigaunts heal Alyx. During the healing process, the G-Man contacts Freeman, stating that he has been prevented from doing so by the Vortigaunts until this point. The G-Man asks Freeman to escort Alyx to White Forest safely and instructs her to tell her father to "prepare for unforeseen consequences." After Alyx has recovered, she and Freeman, accompanied by the Vortigaunt, proceed to the surface.
• Upon reaching the surface, Alyx, Freeman and their Vortigaunt companion observe large group of Combine forces traveling north towards White Forest. Freeman kills the Antlion Guardian before reaching the last Resistance outpost of the Victory Mine, which has been overrun by Headcrabs. Freeman is required to descend into the infested mining settlement in order to reach a working muscle car for the journey to White Forest. Alyx assists Freeman by covering his progress with a sniper rifle powered by the Vortigaunt. Gordon finally reaches the far side of the settlement where the muscle car awaits. He jumps the car over a broken bridge back onto the side Alyx and the Vortigaunt are waiting at. The Vortigaunt takes his leave of Alyx and Gordon, informing them that his kin are hunting "shu'ulathoi" still in their escape pods.
• Freeman and Alyx proceed to White Forest. They discover a radio tower and Alyx decides to try and contact White Forest to warn of the impending attack. While establishing power to the transmitter, Hunters arrive and ambush them. Freeman fights the Hunters directly for the first time and manages to defeat them. Alyx and Freeman resume trying to contact White Forest base but are unable as Advisors appear to be blocking the transmission. Continuing, they investigate a nearby barn and discover an Advisor encamped inside it. Alyx exposes its life support system and Freeman damages it, before emerges from its mechanical cocoon and pins Freeman and Alyx to a wall. Further damage to its life support system forces it to flee. The pair fight off a Combine ambush and escape a Hunter-Chopper which arrives at the barn. They are pursued by the helicopter to the next Resistance outpost, the car's engine giving out as it breaks through a barricade at the entrance.
• After the helicopter is destroyed, Alyx and the rebels work on the car while Freeman disables a Combine Autogun that is hampering Resistance movement. In the meantime, a rebel technician repairs the car and installs a radar detector that picks up Resistance caches. After the car is fixed, Alyx and Freeman continue to White Forest, traveling through the countryside and retrieving supplies from several hidden caches. An enormous Combine ambush is laid for them at the White Forest Inn, but after defeating the attacking Overwatch forces, they approach the White Forest base. They witness a dropship being downed by rebels, however the Strider that it was carrying awakens. Dog arrives and defeats the Strider, and Freeman and Alyx proceed to White Forest.
• Arriving at White Forest, Alyx and Freeman reunite with Kleiner and Dr. Vance, and Alyx finally delivers the transmission packet to them. Freeman and Alyx learn that the White Forest team is preparing a special rocket which they plan to use, in conjunction with Alyx's data packet and the satellite array launched during the Black Mesa Incident, to close the Combine superportal. They are interrupted when a Combine attack penetrates the base. Freeman defeats the attack force and closes the silo doors that are allowing access to the facility. After successfully repelling the attack, Gordon meets up with Alyx, and the two return to Kleiner and Dr. Vance who have completed decoding Judith Mossman's message, in which they discover Mossman's findings about the Borealis. Kleiner suggests using the technology of the Borealis against the Combine, while Dr. Vance insists that it be destroyed to avoid potentially disastrous consequences. Initially, Dr. Vance wants to follow Mossman to rescue her; however, he becomes convinced that his own knowledge of the Resistance is far too sensitive for him to risk capture by the Combine, and Alyx promises that she and Freeman will go after Mossman. After a call from Arne Magnusson, Kleiner leaves to assist him in the final preparation for the launch of the rocket. Alyx delivers the G-Man's message to her father, much to his shock. They are soon interrupted, however, as they are informed of a larger Combine attack force advancing on the base. Making use of several Magnusson Devices, Freeman manages to defeat the attack force in the valley around the base.
• Following the Combine's defeat in the battle of White Forest, the Resistance's rocket is successfully launched, closing the superportal and preventing the Combine from calling in reinforcements from their homeworld. However, as Freeman and Alyx prepare to depart to search for Mossman, Advisors attack the helicopter hangar. Alyx and Freeman are both pinned against the wall as an Advisor is about to kill Dr. Vance; however, the G-Man allows Alyx from five years ago to travel forward in time to this point in order to kill the Advisor before it kills her father. Alyx of the present is then taken by the G-Man. Eli becomes furious when he realizes that she was taken by the G-Man and vows to kill him.

• 

  The wreckage of City 17.

• 

  Alyx Vance attacked by a Hunter.

• 

  The G-Man's "heart-to-heart" with Freeman.

• 

  The Muscle Car above the last Victory Mine outpost.

• 

  The Barn Advisor pulling on Alyx Vance, Gordon Freeman and a dead Rebel.

• 

  The White Forest Inn exterior.

• 

  Strider being destroyed by a Magnussson Device.

• 

  The White Forest rocket lifting off.

• 

  Dr. Vance hands Freeman his crowbar after vowing revenge against the G-Man.

Far Future

Circa 52,000s

• After over 50,000 years in stasis, Chell is awoken by the personality core Wheatley. Wheatley insists he can secure an escape route out of the Aperture Laboratories, which instead results in the inadvertent reactivation of GLaDOS. Chell is forced to make her way through new test chambers controlled by GLaDOS, who belittles her as she makes her way along them. She manages to escape the test chambers with Wheatley's help, and after disrupting the facility's Turret Redemption Lines and Neurotoxin Generator, they make their way to GLaDOS' chamber and confront her. With Chell's help, Wheatley performs a core transfer with GLaDOS and takes control of her body, gaining control of the entire facility. However, after being corrupted by his new power, Wheatley experiences a fit of rage, and after being insulted by GLaDOS, he transfers her into a potato battery and slams her and Chell down into the lower depths of the facility. Chell finds herself traversing old condemned Enrichment Spheres originating from the mid-20th century, at which time Aperture Laboratories was under the direction of Cave Johnson. After reuniting with GLaDOS, the pair continue to traverse through the old facilities until they reach the top of Aperture Science, where they discover that Wheatley has been mismanaging the facility, almost leading to a nuclear meltdown before a climactic standoff between Chell and Wheatley, which results in Wheatley being trapped in Earth's orbit. Chell falls unconscious after arriving back on Earth, and GLaDOS regains control of the facility.

• 

  Chell's Relaxation Chamber, now visibly damaged.

• 

  GLaDOS awakens in her ruined chamber.

• 

  Turret Redemption Line.

• 

  Chell discovers the now potato-powered GLaDOS in a crow's nest.

• 

  Chell and GLaDOS facing Wheatley.

• 

  Wheatley with all the cores placed.

The next day

• After Chell regains consciousness the next morning, GLaDOS expresses relief about her survival, before deleting Caroline's consciousness from her brain and saying her final goodbyes to Chell, sending her outside. Shortly after Chell's departure, GLaDOS turns onto testing two testing androids, ATLAS and P-body. They are assigned to carry out a series of tests in six different courses, each consisting of about eight or nine chambers. At the end of each course, GLaDOS sends the androids outside of the testing chambers and into the facility itself, claiming their help is needed to retrieve several Compact Discs "innocently" left lying around by humans; in reality, she is using the androids to help her gain control of the facility. After all the courses are finished, GLaDOS is able to access a vault in the lower levels which contains hundreds of human test subjects. She has determined that, given their inability to die, ATLAS and P-body aren't as fun to test with as human test subjects. They are sent to open the vault, and upon reaching it, they open it by making similar gestures to the camera installed on the lock. GLaDOS claims to have more work for them as she destroys them.

• 

  Back exit of Aperture Laboratories years in the future.

• 

  The Hub.

• 

  Inside the Human Vault.

One week later

• GLaDOS rebuilds ATLAS and P-body, claiming that 100,000 years have passed since the conclusion of the last course. She guides the two of them through a new set of courses as a number of mechanical failures occur, which GLaDOS attempts to cover up. Eventually the reassembly machinery fails, forcing ATLAS and P-body to make a detour through an incomplete test track. GLaDOS admits that she has been lying and reveals that she had killed all the remaining humans during testing, and that it has only been a week. GLaDOS believes that Chell has returned and has gained control of an old mainframe chassis, posing a threat to the facility. In the final chamber, GLaDOS informs the two that the reassembly machines have broken down and that if she doesn't regain control, their next deaths will be permanent. The robots reach the chassis, but find that it is being controlled mindlessly by a crow nesting. Despite GLaDOS' calls for a retreat, ATLAS shoos the bird from the control panel and P-body manages to lock it out of the facility. GLaDOS then notices that the crow had been harbouring three eggs, which she hatches in an "oviparous warming vault," planning to breed the chicks as "little killing machines".

• 

  The three crow chicks under GLaDOS' care.

See also

• Canon
• Retcons