When his girl commits murder, a hardened criminal takes the rap to protect her honor.

Tommy Connors, a cocky tough guy, is sent to Sing Sing but is confident that he will not have to follow the rules of prison life. When his smooth lawyer, Joe Finn, tries unsuccessfully to bribe warden Paul Long, however, it becomes clear that Connors is now just another number. Connors and Long battle in a contest of wills, in which Long practices his modern theories of reform. Long begins to see results when Connors does not participate in an escape attempt designed by educated convict Bud Sauders. Eventually, Long puts his honor system to the test when he trusts Connors outside the walls. Hoping to help, Connors' girl friend, Fay Wilson, makes friends with Finn, but when he attacks her during an automobile trip, she jumps from the car and is badly injured. Long allows Connors to visit Fay, who is critically ill, but upon discovering that Finn is responsible for her injuries, he initiates a fight. Fay shoots and kills Finn, but it is Connors who is convicted for the murder. After Fay recovers, Connors is sentenced to death, and the couple is briefly reunited on death row. Fay attempts to confess her crime to Long, but her pleas are in vain. Connors is left alone to face the electric chair, asking only for one last cigarette.