A young girl, Mary Tillet, is forced to find a new place to live due to her London home being bombed during World War II. Her tobacconist landlord, Jack Rawling, tries to help her turn her new apartment into a home. Meanwhile the newspapers are reporting news of the "London Blackout Murders," a murder spree being committed against a ring of suspected Nazi spies, and Mary must determine if her kind landlord is an assassin.

An American joins the British Royal Air Force just before Pearl Harbor is attacked, and falls in love with a beautiful English girl.

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.

Wealthy, sheltered Lina McLaidlaw is swept off her feet by charming ne'er-do-well Johnnie Aysgarth. Though warned that Johnnie is little more than a fortune hunter, Lina marries him anyway and remains loyal to her irresponsible husband as he plows his way from one disreputable business scheme to another. Gradually Lina comes to the conclusion that Johnnie intends to kill her in order to collect her inheritance.