The year is 2147. Chago, twenty-four, is a prisoner in a world made up only of prisoners and those who guard them. The only bright spot in Chago's life is his son, Jim-Jim, whose mother is a guard. In an effort to resolve overcrowding in the prison, the warden introduces the Innocence Device, a high-tech machine he claims can determine innocence or guilt. Prisoners are encouraged to walk through the Innocence Device and experience its rewards: immediate freedom or death. When they discover the machine is rigged, the prisoners riot and take over the prison.