Late in World War II, the Brits still want their hands on a German Enigma, the typewriter-like machine that constructs and sends coded messages.
Parachuting behind enemy lines - with two days to find the factory where Enigmas are made, grab one, and get out - are an unlikely quartet: a queen, a pencil pusher, a bookworm, and an almost secret agent.
Plus they are all dressed as women, with only a crash course from the queen. They reach their destination, rendezvous with their German contact, a lovely librarian, and start their search.
They seemed doomed to fail; is this a fool's errand?