Many superstitions are based on fact.
Warning: Spoilers
John Brahm's film is an adaptation of the novel written by Jessie Douglas Kerruish. Following the success for Universal with The Wolf Man a year earlier, 20th Century Fox clearly saw an opportunity to cash in on the renewed interest in Lycanthropic creatures. Brahm's film deals with one such legendary creature that is said to terrorise members of the cursed Hammond family. Roping in master photographer Lucien Ballard, Brahm sets the film up with the creepy ancestral home atop of a cliff, the sea on one side, the foggy moor on the other. Then with minimal budget and a cast of largely minor players-and a short 23 day production schedule, Brahm crafted a tight, eerie mystery that deserves far better appraisal than it's currently getting.
Atmosphere is of paramount importance when making a Gothic type picture, The Undying Monster has it by the bucket load. Aided by Ballard's adroit skills, Brahm excellently uses shadows and light to garner unease, be it the interiors that are gorgeously designed, or the foggy exteriors perhaps hiding dark secrets, atmosphere is high quality here. The film has been chided in certain quarters for either being too talky, or for daring to be jovial at times. Yes these charges are fair if one is expecting an outright horror film and not the creepy mystery that it actually is. This is no boo jump bonanza, the creature is purposely kept from us so as to keep us, and the characters wondering when, or if, it will show up. Thus the conversations become crucial and of high interest. Something that hasn't helped the film either is its title, why they didn't go with the first muted {and English title} name, "The Hammond Mystery" is probably due to the afore mentioned attempt to cash in on The Wolf Man. As you can see, one screams out that the film is about a monster who can't be killed, the other sounds like it's an Agatha Christie who done it?. You understand their reasonings, it's just very misleading and hasn't helped the films reputation to flow.
It's a cracking mystery film that has horror elements involved in its plot. More like The Hound Of The Baskervilles than The Wolf Man, it none the less is 63 minutes of 1940s Gothic joy. 8/10