Tommy and Tuppence, two young people flat broke and out of work, are restless for excitement. They embark on a daring business scheme - Young Adventurers Ltd -"willing to do anything, go anywhere".
But their first assignment, for the sinister Mr Whittington, draws them into a sinister, political conspiracy. Under the eye of the elusive, ruthless Mr Brown, hey find themselves plunged into more danger than they ever imagined.