This French-Italian joint was a little strange to watch in that, for long stretches, the dialogue would lapse into a foreign language there was no attempt to translate. I don't know what they were talking about, but I sure wish I did. The only other real complaint I have is the slowness of the first 20 minutes or so. It is literally just a guy walking around an empty blood-free castle. Snore.
Let me set the scene: Alan Foster is a reporter who has tracked down Edgar Allen Poe (?!) to ask him about his stories. Poe is dining with a Lord Blackwood and they invite Alan to join. Poe basically says that all his stories are thinly veiled descriptions of things that really happened to him. Then he speaks in a foreign language for a long time. The next English dialogue is Lord Blackwood betting Foster that he can't spend the night in Blackwood's haunted castle alone. This leads to the interminable scenes of Foster wandering the castle and checking it out by candlelight. He finally runs into Elizaneth Blackwood, the Lord's hot sister played by Barbara Steele. Foster and Elizabeth hit it off but are cock-blocked by Julia, a blonde lady who lives at the house for no known reason. Foster thinks she is foxy, too, and hits on her as well. People keep vanishing and appearing and before too long, Foster figures out he is surrounded by ghosts. Or vampire ghosts. Or something. This movie is kind of vague.
The ghost of a previous guest who took on Blackwood's bet, a spiritualist named Carmus, becomes Foster's guide through the horrible history of the house. Foster gets to see every death played out in front of him by the ghosts. Kind of late in the game, one informs him that they need his blood to live again this time next year and thus the last ten minutes or so become Foster running for his life inside a haunted castle.
The movie has a lot of sex in it for a black and white film (even nudity, that I found surprising) and deals with it in a frank way. Foster is a complete goober so we never really pull for him but Barbara Steele's Elizabeth makes a sympathetic figure in that EVERYONE in the castle wants to bone her and she just wants true love. All in all, not essential but interesting enough to watch once.