Half-Life Blue Shift-Duty Calls

Barney Calhoun regains consciousness at the bottom of the elevator shaft to the sight of a houndeye eating the body of a fellow security guard. The two scientists in the elevator are dead, and so Calhoun sets off through the industrial waste areas of Black Mesa to try to find help. Along the way he gains an insight into the scope of the disaster, and sees a pair of marines dumping corpses into a sewer opening, thus discovering that the military is trying to cover up the disaster rather than evacuate surviving personnel.