Dead-tired Karen a young psychiatric nurse catches the last subway train of the night. Before long she finds herself trapped along with a handful of other late-night passengers fighting for their lives against the murderous zealots of a doomsday cult. Now as the bodies start piling up Karen and the rest of the lucky survivors must fight tooth-and-nail to stay alive facing the unknown and the impending apocalypse. But at the end of the line there is no place to go but down.