Two men have just arrived at a location known as Quindecim and are unable to remember how they got there. They are immediately greeted by a young woman who escorts them to a small bar, where a bartender awaits them. They are told that they will have to participate in a game, randomly chosen by roulette, and will be unable to leave until its completion; if they refuse, the consequences will be dire. In addition to the rules of the game, the two men are told to play as if their lives are at stake.