
Henry, a staid accountant, comes upon a fortune in used currency notes. The chance of a lifetime tempts him to escape with his wife, Jean, on the first flight out of London. Guests for his 60th birthday dinner hamper plans, while a crooked policeman, Sergeant Davenport, who has been watching Henry's shenanigans in the pub begins blackmailing him.
The stash of cash, mistakenly appropriated, has been used for illicit transactions. The mafia is furious, a body is found in the river. A policeman, Sergeant Slater, comes calling. The single-minded purpose to fly off from London is assisted by and hampered by Bill, the London taxi driver. All roads seem to point to Barcelona with outrageous cover-ups, leading to an exciting climax.