Major Freddie Oppenheimer (Bill Travers) – who has lost a leg – is in a British Army Rehabilitation Hospital in 1942 during the early days of the Second World War with Frenchman Major Pierre Debrie (Grégoire Aslan), who has lost a hand; the Colonel (John Le Mesurier), who has been deemed too old for active duty and placed in charge of the Kent Home Guard; and shell-shocked explosives expert Godfrey Pringle (Spike Milligan).
The four men are under the somewhat addled care of former gynaecologist Dr Barker (Maurice Denham), who doesn’t understand his male patients.
With the exception of Pringle, who suffers a noise neurosis, they want to get back into the fighting.
They plan to blow up “Big Herman” – the big German gun which has been shelling Dover from across the English Channel – and, after stealing a small boat from the Royal Navy and ammunition from the local Home Guard store, they set sail for occupied France.
More by luck than judgment, they manage to escape the hazards of mines and German patrols and arrive intact.
What is more astounding, this unlikely quartet manages to complete its mission and causes utter havoc among enemy forces – without acquiring so much as a scratch themselves.
Major Freddie Oppenheimer
Major Pierre Debrie
John Le Mesurier
Duty Officer – War Office
German Band Conductor