Veteran gangster Gustave (Lino Ventura) escapes from prison to find his sister is being blackmailed by some petty thugs in this crime thriller. He plans one last caper to steal enough money in hopes of retiring to a tropical paradise. He and his gang are sought by a detective (Paul Meurisse), the cop who plays by the book and avoids the sadistic torture practiced by his less-honorable cohorts. Soon Gustave is caught between the police and the double-crossing gangsters and discovers too late that there is no honor among thieves.