I really don't know how this movie can have such a great cast and still be so boring. It's about a guy who uses an ancient Indian drug that he calls "The Black Sleep" to simulate death in his patients so he can bring them back (hey, didn't we just see this in "White Zombie"?) That's pretty much the premise of this movie, that this guy uses this drug on people because he has an ulterior motive for studying how people's brains work: his wife is in a coma and he wants to operate on her and save her. The premise sounds good, but the movie is so boring that it wastes a good idea and a solid cast. Mostly all that happens is people wander around the castle where this doctor performs his experiments. It's all pretty silly when it's not busy being boring. I wish I'd watched something else.