In 1940 England, aristocratic Prudence Cathaway alarms her snobbish parents by joining the WAF service branch. She soon meets and falls in love with the brooding Clive Briggs, despite his prejudice against the upper classes, and agrees to spend a week with him at a Dover hotel. When Clive's soldier friend, Monty, arrives to retrieve him, Prudence learns that Clive went AWOL after Dunkirk, and urges him to recall why England must fight the war.

Shortly before the start of WW2, renowned British big-game hunter Alan Thorndike, vacationing in Bavaria, has Hitler in his gun sight. He is captured, beaten, left for dead, and escapes back to London where he is hounded by Nazi agents and aided by a young woman.

Lord Windermere appears to all – including his young wife Margaret – to be the perfect husband. The couple's happy marriage is placed at risk when he starts paying visits to a mysterious beautiful newcomer, Mrs. Erylnne, who is determined to make her entry into London's high society. Worse, the secret gets back to Margaret that Windermere has been giving Mrs. Erylnne large sums of money.