Though it's not a particularly good film, "Cottage to Let" is interesting to consider, both as wartime propaganda and with regards to genre.
Released in late summer of 1941, production would have had to begun right after the declaration of war between in England and Germany. Since it was based on a stage play by Geoffrey Kerr, someone must've been dreaming this thing up not long after Poland fell.
The bad guys are shifty German agents who have infiltrated seemingly every nook and cranny of the United Kingdom, including remote Thrail Manor in the Scottish moors. Essentially it's an Agatha Christie-ish whodunit, except instead of trying to find the murderer we're attempting to discover which of the residents, or which ones, are the Nazis.
The movie's title was later changed to "Bombsight Stolen," which may just win the award for worst film title, ever. Though "Cottage to Let" isn't much better, suggesting a frothy romance about Brits on vacation.
Narratively, the movie is structured like a slamming doors, upstairs/downstairs comedy of manners with plenty of potboiler elements mixed in. The audience's alter ego is Ronald (George Cole), an "evacuee" boy -- moved out of London amidst the bombings and forced to live in the country manor of the Barringtons. Ronnie is a puckish lad who takes Sherlock Holmes as his personal hero, believing him to be an actual historical figure. Soon he's sleuthing out clues all over the estate.
Mrs. Barrington (Jeanne De Casalis) is the adorably absent-minded matron trying to run various war fundraising efforts and social cotillions in the midst of urchins left at her doorstep, injured RIF Spitfire pilots being dumped into her lap and her eccentric inventor husband, John (Leslie Banks), in danger of blowing up the place.
Mr. Barrington is supposedly the most brilliant scientist in the U.K., though he stubbornly insists upon working in his isolated laboratory with a single assistant, Trently (Michael Wilding), rather than in London surrounded by military and intelligence handlers. Unfortunately, there's a leak somewhere in Thrail Manor, and some of Barrington's best inventions -- such as a self-sealing airplane fuel tank -- are getting into the hands of the Germans almost as soon as they go into production.
The injured pilot is Perry (John Mills), a dashing young officer who clearly is up to something. Director Anthony Asquith and screenwriters Anatole de Grunwald and J.O.C. Orton show him unplugging and re-plugging the phone to report his downing while lying bloodied and bandanged in a hospital bed at the cottage next to Thrail Manor, so we immediately know he's a bad egg. Soon he begins to woo his nurse, young Helen Barrington (Carla Lehmann), which puts the long-suffering, amorous Trently into a fit.
The M.O. for this story appears to have been to cast doubt on half of the cast members, and see who cracks. Trently is under suspicion because he was educated in Germany and traveled there before the war. The butler, Evans (Wally Patch), is a little too martial in his bearing and clumsy in his housekeeping skills to be a simple servant. The cook, Mrs. Trimm, quits suddenly in a huff, and confers with Trently after giving her notice.
Then there's Dimble (Alastair Sim), a strange bird of a man who has rented out the cottage before all the new boarders arrive. Tall, thin and with a false sense of friendliness, Dimble pokes his nose into everybody's business, often while peeling a potato with a penknife.
It would seem amateurish to make Dimble, so homely and awkard compared to the rest of the cast, the Nazi stooge, and the filmmakers pull a reversal on us near the end that's supposed to be a head-snapper. But I figured it out barely a third into the movie, and I doubt if any audience members wouldn't do so, too.
The stage roots, and flaws, of "Cottage to Let" are glaring -- a limited number of locations, who's-your-uncle dialogue repartee, a romantic angle that feels tacked-on and unnecessary. I rather liked Leslie Banks as the bumbling-but-decent inventor, but his limited screen time registers him as more a sideshow than the star of the picture.
Maybe if they'd made Ronnie the Boy Detective the bad guy -- then we really would've had something.