As almost always was the case with Hammer, this is a rather studiobound, but still lavish-looking movie (shot by the always reliable Arthur Grant who had almost a midas-touch when it came to cinematography), despite it's low budget. You also get a long list of old pros like Andrew Keir and Rosalie Crutchley in important parts plus the sultry charms of Valerie Leon, former model and star of british sex-comedys. She is not the greatest actress in the world but does a very competent job with her part, managing the sudden moodswings convincingly. The story is based on a lesser-known Bram 'Dracula' Stoker novel, filmed two more times ('The Awakening' is big-budget but does nothing with all those bucks, just manages to be mostly boring even in the murder-scenes). It does not feature the usual, gauze-wrapped, mummy but it is instead a tale of possession. It is maybe a bit talky in places, but the atmosphere is always right and menacing. Main director Seth Holt died during the last days of shooting so producer Michael Carreras had to do the scenes in the asylum and they are among the most impressive. Horrormovie-fans today will probably find this movie incredibly old-fashioned, but if you are tired of the hundreth film about Jason, Freddy or your average neighborhood slasher, give this a second glance.