A genetically-engineered virus originally created as a cure for the common cold turns into a lethal strain. It kills 75 percent of those it infects; mutates 23 percent into flesh-eating, zombie-like creatures with incredible strength and speed; and 2 percent appear to be immune. The virus has infected people in major cities around the world. Those bitten by the infected either die or become infected creatures themselves within thirty seconds of the bite. In order to save the human race, research facilities are popping up all over the world to research some of those infected hoping a cure can be found. They also evacuate the non-infected to other cities known safe zones. In one major research facility the infected have overpowered the guards and broken free within the building. To stay alive (and uninfected) you must work your way through a maze of rooms filled with genetically-engineered, zombie-like creatures. Get to the transport trains and out of the building to the next safe zone.