The presence of Boris Karloff may lead many to think that Night Key is a horror film, but in fact it is instead a rather routine crime melodrama. While the film itself is at best enjoyable, Key is really worth watching for one of the rare opportunities to see (Karloff not only in a non-horror film but also in a "good guy" role. True, Karloff's character does participate in robberies here, but that's to right a wrong done him and, later, to protect his daughter from harm. The actor is, in fact, quite kind, gentle and fatherly in Key, and while the film doesn't exploit the unique facets of his talent, it does show that he easily could have essayed a wider range of roles had the opportunities presented themselves. Also in the cast is Hobart Cavanugh, in a good turn as Karloff's duplicitous partner and Jean Rogers, appealing and attractive as his daughter. The screenplay isn't much to write home about, and Lloyd Corrigan's direction is by-the-book, but Key is at least swiftly paced.