On Christmas Eve morning, a terrorist sets off an explosion at a Federal building to expose the government's secret biological warfare weapon, a deadly virus that instantly attacks a person's adrenal system, causing them to become inhumanly aggressive. Now everyone below the sixth floor is infected with an uncontrollable urge to kill. In order to contain the situation, the government initiates a countdown that will detonate the building and bury their secret. With the time bomb ticking, a group of uninfected employees must band together and fight to get past the infected and out of the building alive. But they soon realize there may be no escape; whatever happened in this building is not intended to get out.