Corporal Adrian Shephard is a 22-year old
US Marine Corporal assigned to the
Hazardous Environment Combat Unit from the
Santego Military Base, Arizona, where he was trained by Drill Instructors
Dwight T. Barnes and
Sharp, and the silent protagonist of
Half-Life: Opposing Force. He is one of the men sent in the
Black Mesa Research Facility to kill the
Xen invaders and later silence the witnesses, especially a scientist named
Gordon Freeman, as part of a classified mission. Early in the game, Shephard finds himself separated from his unit and ends up fighting for his life only, aided by fellow Marines scattered around the facility and Black Mesa employees.
