Perhaps the key to enjoying this movie is to come to it with no expectations, as I did--or to be a fan of William Castle (as I am becoming!). If you know William Castle's work, you know to expect low-budget chills that don't take themselves very seriously. What's surprising about this film is that it's actually fairly sophisticated. The plot has some excellent twists; the chills are more psychological and less gore-dependent than in other Castle films I can think of; and it's just fun to see two great (albeit aging) stars get their teeth into a horror script. Barbara Stanwyck is excellent, and Robert Taylor comes a close second.
Why this little gem isn't available on DVD with (what I consider to be) lesser Castle works baffles me. It's definitely worth seeking out for your next cheesy horror fest.