Secombe plays the part of Harry Flakers, a man who has a big win on the football pools. He and his friend Spike Donnelly (Milligan) decide to go to the same shabby seaside boarding house that they have always patronised for their summer holiday, but this year all the other guests (including two young women out to marry money, a dodgy investment advisor and a master forger and assistant) are intent on taking the fortune off them in one way or another.
Ultimately the forgers manage to substitute fake five-pound notes for the real ones that Flakers keeps in his suitcase, but before they can abscond with the money one of the girls is given cash by Flakers to buy some cigarettes, and accused of passing false currency when the forgery is detected. A grand chase follows with half the characters pursuing the other half through a waxwork museum in which the true crooks have taken refuge. Justice is served when the chief forger boasts of his crime in front of what he thinks are two waxwork policemen, but who turn out to be real members of the force.
In the final scenes Harry and Spike get married to the two women.
There are sequences featuring a night out at the theatre where a stage hypnotist mesmerises Flakers and the girl Christine into performing an operatic duet, he singing soprano and she baritone, and a scene in which Harry Secombe wordlessly mimes out an entire heart operation being carried out by a nervous surgeon.
- Harry Secombe as Harry Flakers
- Alfred Marks as Edward Haynes
- Peter Sellers as The Major / Arnold Fringe
- Paddie O'Neil as Christine Russell
- Spike Milligan as Spike Donnelly
- Bill Kerr as Digger Graves
- Freddie Frinton as Drunk
- Vicki Page as Sheila Gilroy
- Joe Linnane as Policeman
- Sam Kydd as Porter / Taxi Driver