Description: John Mills plays a sailor, who tells his fiancée the sailing-time of his ship ("HMS Cambridge") while in a cafe. A sentimental waitress overhears and innocently tells the manageress, who is an agent - the news is passed on by a meeting in a cinema, a cryptic phone call, and finally flashed out to a passing ship. The ship in turn contacts a U-boat, and the Cambridge is sunk, with the loss of John Mills and many others.
