James McQueen is known as 'The Lock', a criminal whose fame in the underworld is almost legendary because of his skill and knowledge with safe combinations and key patterns. 'The Lock' is sprung from prison by a gang led by his son Wayne in order to pull a major job. To his son's dismay, 'The Lock' refuses to commit the job he was released to do, his years in prison having given him strong food for thought about the hopelessness of the criminal life.