Cottage to Let is a taut British wartime spy thriller, laced with moments of genuinely hilarious comedy. The "maguffin" in this instance is a revolutionary new bombsight, designed by inventor John Barrington (Leslie Banks). A group of Nazi spies intend to steal the blueprints for the invention (hence the film's alternate title Bombsight Stolen), and to that end dispatch one of their top agents (John Mills), who parachutes into the story posing as wounded RAF pilot Lt. Perry. Hailed as a war hero by the gullible locals, Perry rents a cottage from the unsuspecting Barrington and his wife (Jeanne de Casalis). The treacherous Nazi meets his match in the unlikely form of oafish Charles Dimble (Alastair Sim), who turns out to be a British undercover agent.