John Flinders is the warden at Red Rock Prison in the Arizona Territory in 1910. Considered stern but humane, he supervises this penal institution fairly and without corruption. To fulfill the last request of a condemned prisoner, Flinders agrees to return a wedding ring to the prisoner's wife and finds himself attracted to her. Flinders confesses his feelings to his good friend and ponders whether he has devoted too much of himself to the law and not enough time on matters of the heart. Meanwhile, hardened prisoner, Mike Sullivan, is transferred to Red Rock. The guards and prisoners fear him, but to their surprise Sullivan and Flinders know each other from when they were both outlaws in Mexico. While Flinders reformed and devoted himself to the law, Sullivan continued with cattle rustling and armed robbery, until eventually he was sentenced to life imprisonment on a murder charge. Now Sullivan is determined not to spend his life behind bars and Flinders is determined to keep him there...