It's been 30 years since I saw this film, and most of what I recall about it is that I loved it, as a 10-year-old watching at 4 a.m.

I distantly recall a tale of bringing life back with a dark, brooding sinister Karloff obsessed with a purpose. There was of course, a young couple in danger. I recall dark sets, with much of the action in a dark room, or maybe it was even a cave. As I mentioned, it's been a long time. I wish I could recall more, and find this film gem. Does anyone know if a DVD or video company sells this classic of the genre?