Night Key is in no way, shape or form a horror movie, although it was included in the Shock Theater package of syndicated films and stars Boris Karloff. There's a hint of science fiction, though, as inventor David Mallory (Karloff) uses technology of the time to help he and his daughter, Joan (Jean Rogers), escape from mobsters who have kidnapped them for access to alarm systems of various companies and retail stores. A harmless blackmail plot by Mallory, so that Stephen Ranger (Samuel S. Hinds) will install his new system, turns dangerous when it falls into the wrong hands.
I was somewhat fascinated by this little movie, partially due to its primitive treatment of security systems as advanced technology. It seemed to have a real flavor or the era. Karloff is great in a different kind of role, kind of like a lovable grandfather. It's surprisingly entertaining, even though slight.