The last thing Kei remembers is the train running over his body. Now he is in a room filled with strangers, all resurrected by the featureless black sphere known only as the Gantz. But their reprieve from death may only be temporary, for unless they undertake the brutal missions that the Gantz assigns, none of them will live long enough to leave the room. Is it a game? A nightmare? All Kei knows is that if they fail, they will die again.