Now its a race against the clock as you fight your was through infested alien nesting grounds and military blockades while constantly trying to reach the surface and get out of here alive. Unfortunately, that may not be as easy as it sounds, because the military has decided that rather than kill every witness individually, they are going to simply seal off all of the exits….and then set off a thermal nuclear weapon. Now your trapped in an alien-infested hole in the ground with only one objective – reach the surface alive. To top it all off, most of the inhabitants of Xen have used their natural instinct to migrate here since the destruction of their home planet, and rifts in space time continue to throw Xen creatures into the bowels of Black Mesa. Hallways and staircases are sealed – collapsed by air-strikes. Corpses lie mangled in pools of their own blood. When you regain your conciousness, sirens and screams are all you hear as you wake up to the reality of utter chaos and destruction. And thanks to a teleport malfunction you are back right where you started… four kilometres underground in the darkest corner of the Black Mesa Research Facility. You decided that your pride was more sacred than your safety. All that you had to do was just take the job. “Otherwise… well… I can offer you a battle you have no chance of winning….rather an anticlimax, after what you’ve just survived…”

The Replay Experience Experiment aka TREE.

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