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, portrayed by actor John Abbott, 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.
