This film is based on the book of the same name by Dennis Wheatley. The Duke du Richeleau (Christopher Lee) and his friend Rex Van Ryn (Leon Greene) had been expecting to meet up with their young ward, Simon Aron (Patrick Mower), for a pre-arranged meal.

They go looking for Simon to find out why he didn't turn up, only to discover that he had joined an exclusive "astronomical society". Du Richeleau believes that the young man has fallen in with a Satanist Cult, which is leady by a man called Mecata (Charles Gray). At the party Rex takes a shine to a young woman called Tanith, who it turns out is the medium that Mecata requires for his occult practices.

The Duke must fight time, evil and scepticism to save his friends.

Christopher Lee is excellent as de Richeleau, and is matched by the malevolence of Charles Gray as the evil Mecata. Of the entire cast, the weakest for me has to be Patrick Mower (but he was only at the start of his career in this film).

This film was made as part of a deal with Christopher Lee (who was a fan of Dennis Wheatley's work), and is said to be one of his favourite films. Mr Lee is one of my favourite actors, so I may be a little bias.

I have to say that I have been a fan of Wheatley's work since I was a child, but when ever I managed to save enough to get a book my father would find it and, when I came home from school, we would have a ritualistic destruction of the text, along with comments about witch-craft, black magic and the occult. I hate to think what he'd do to my collection if he could see it now.