Gaumont British Picture Corp.

An Englishman and his wife and child become involved in a plot to assassinate a foreign diplomat. The child is kidnapped before her father can turn a coded message over to the British Foreign Office.

Follows the escapades of Richard Hanney, who stumbles into a conspiracy that involves him in a hectic chase across the Scottish moors.

A young woman on a train, enroute back to England from Switzerland, meets a charming older lady who promptly disappears. The other passengers deny ever having seen her, leading the young woman into a complex web of mystery and high adventure.