Alan Dobie plays a convict who is bequeathed a set of seven keys by a fellow prisoner. After discovering that the deceased was an embezzler who stole £20,000 that was never recovered; he sets out to find the cash after finishing the last three months of his sentence. However he must first solve the mystery of which locks the keys fit, and run the gauntlet of the police and a number of gangsters who are after him and the money.
as Shirley Steele
as Russell
as Natalie Worth
as Norman
as Jefferson
as Governor
as Mr. Piggott
as Mrs. Piggott
as Warder
as Mr. Barber
as Estate Agent
as Freddy
as Police Sergeant