|Directed by||Ken Annakin|
|Produced by||Leslie Parkyn|
|Written by||Henry Blyth|
|Edited by||John Trumper|
|Distributed by||Anglo-Amalgamated Film Distributors|
Captain "Dandy Forsdyke" (Leslie Phillips) is a habitual criminal who can't resist a tempting robbery. His gifts are for pickpocketing and safecracking and even does not use his real name. However, he is engaged to Babette (Julie Christie), a stripper who wants him to go straight before they marry.
In love with Babette, he desperately wants to quit, but is always lured back into another crime by his associates. Babette comes across a society known as Crooks Anonymous who help hardened thieves go straight. Founded by Mr Montague (Wilfrid Hyde-White), and funded by a generous legacy, they have an excellent track record. Babette agrees to help them cure Forsdyke.
Forsdyke is picked up during a robbery by a Crooks Anonymous man, Brother Widdowes (Stanley Baxter), who is disguised as a policeman, and taken to the Crooks Anonymous headquarters. Confronted by Montague, Forsdyke admits that he wants to give up crime and marry Babette. They begin to interrogate him, and discover that he is a habitual liar, whose real name is Cox, who has never seen military service, despite his claim to be a decorated veteran.
Widdowes and Montague embark Forsdyke on a dose of punishment therapy and rehabilitation. They begin by locking him in a room filled with safes, which contain cigarettes, food, drink and a number of booby traps which make opening them a hazardous business. After a week of this torture, Forsdyke is beginning to crack. Nonetheless, he fails a test to see how much progress he has made, reverting to his old ways as soon as he is outside.
After a month of correctional therapy and reinforcement training, Forsdyke finally passes the test and is released into society. He moves into a house with Babette, gets a job working as Father Christmas in a department store and refuses an offer by one of his old pals to go back into criminality.
However, after consuming large amounts of alcohol at a Christmas party he passes out and finds himself alone in the department store, with £250,000 of takings near him in the safe. Forsdyke breaks in intending to steal the money, and then panicking at his relapse, calls Crooks Anonymous for help. They send their two top men, including Brother Widdowes, who also cave at the sight of the money. They in turn call for the Chairman who arrives with his Secretary.
Confronted with this unique opportunity, the five of them decide to steal the money and split it among themselves. They make good their escape, past the drunken night watchmen and head through the streets. They go to Forsdyke's house, only to be confronted by an outraged Babette, who demands they put the money back. Grudgingly they agree, as she threatens to call Scotland Yard and inform them of the burglary.
They successfully manage to return the money, unfortunately triggering an alarm which brings the night watchmen out. Just making good their escape, they breathe a sigh of relief. Forsdyke marries Babette and as a sign of appreciation they make her a Sister of Crooks Anonymous for keeping them all honest.
- Leslie Phillips - Captain "Dandy" Forsdyke/Fred Cox
- Stanley Baxter - Brother Widdowes
- Wilfrid Hyde-White - Montague
- Julie Christie - Babette
- James Robertson Justice - Sir Harvey Russelrod
- Michael Medwin - Ronnie
- Pauline Jameson - Prunella
- Robertson Hare - Grimsdale
- Raymond Huntley - Wagstaffe
- Dermot Kelly - Stanley
- Norman Rossington - Bert
- Harry Fowler - Woods
- Charles Lloyd-Pack - Fletcher
- Harold Goodwin - George
- Harry Locke - Fred
- Colin Gordon - Drunk
- Jeremy Lloyd - M.C. at the Peekaboo Club
- Dennis Waterman - Boy in park
- Bryan Coleman - Holding
- Arthur Mullard - Grogan
- Joyce Blair - Carol
- Timothy Bateson - Partrige
- John Bennett - Thomas
- Victor Brooks - Police Officer
- Julian Orchard - 1st Jeweller
- Patrick Newell - 2nd Jeweller
- Alfred Burke - Caulfield
- Arthur Lovegrove - Jones
- Cardew Robinson - Wiseman - Helicopter Brother
- Dick Emery - Reginald Cundell
- Totti Truman Taylor
- Joby Blanshard - Peekaboo Doorman
- Frank Gatliff - Policeman in the park
- Marianne Stone
- Jerold Wells - Sydney - large Nightwatchman
- Dandy Nichols - Mrs Cundell