AllMovie

In this fifth film version of the play by George M. Cohan and Earl Derr Biggers, Phillip Terry portrays a mystery novelist who wagers that he can write a complete story in one night. To this end, he arranges to sequester himself in a remote rustic inn, assuming that he has the only key to the place. As the evening wears on, the inn becomes the rendezvous for several mysterious characters--all of whom have keys of their own--and the site of a startling murder. Terry tries to figure out the goings-on, but just when he's put the clues together, the lock in the door clicks. The seventh key! We'll withhold the climactic dual plot twist for the benefit of those who've never seen any of the filmizations of Seven Keys to Baldpate, including the misbegotten 1983 version House of the Long Shadows (which starred Desi Arnaz Jr.!)