The Gamma Labs is a Black Mesa Research Facility area partially located topside and introduced in the Half-Life: Decay chapter Crossfire.
This facility was originally used "as a sort of cross-dimensional netting ground", where organic alien samples and creatures were captured from Xen without the need of actually going there, with the Displacement Beacon Focus Emitter located in the nearby canyon, and powered by three Xen crystals channeling the power from the beam matrix located in the Alien Quarantine Labs located below. In Decay, Gina Cross and Colette Green must activate the Focus Emitter to create a Resonance Reversal, and seal the rift between Earth and Xen. This is where the final Decay battle against a Alien Craft, Alien Grunts and Vortigaunts occurs, in the Focus Emitter canyon.
This section is in the middle of an expansion or major revamping.
 List of appearances