Deep in the deserts of southwestern United States lies "Neo Purgatory." Formerly a nuclear waste disposal site, the facility has been turned into a prison for hardened criminals; that is, until the prisoners weaponize the nuclear waste and riot, turning Neo Purgatory into an international disaster. Maki Aoba, Doris Nicholas, Marilyn Moreau, and Naomi Jones make up the "Guard of Rose," an all-female special police task force. Along with stowaway Katherine Hook and multi-purpose robot Link, the Guard of Rose is on patrol investigating rumors of an "angel" near Neo Purgatory when their helicopter is shot down. As the crisis within the prison rapidly devolves, the Guard of Rose members might be the only ones who can stop the prisoners before they unleash nuclear armageddon.