A forgotten classic of the genre, John Brahm's film was first designed by Fox as a B-film to cash in on the success of Universal's The Wolf Man. But Brahm's handling of the werewolf theme has a subtlety that owes much more to Val Lewton's RKO productions than to Universal's excessive style. Like Lewton, Brahm relies more on suspense than shock, and more on atmosphere than make-up. Lit in the wildly baroque manner of Brahm's The Lodger and Hangover Square, The Undying Monster remains an uncommonly impressive and intelligent horror film.