In a massive, mysterious chamber, fifty strangers awaken to find themselves trapped with no memory of how they got there. Organized in an inward-facing circle and unable to move, they quickly learn that every two minutes, one of them must die... executed by a strange device in the center of the room. At first, the attacks seem random, but soon the strangers realize that they, as a group, have the power to decide who will be the next to be killed. A vote. A chance to control the machine.