While the Hammer library is full of different takes on Dracula and Frankenstein, their adaptation of this Dennis Wheatley novel - via a Richard Matheson screenplay - is a stand out entry which exists without the usual monsters. Christopher Lee gets to fight against the forces of evil rather than embody them this time around in a story about devil worshippers and black magic. In some areas it's just as silly as you'd expect a 1960s take on the subject matter would be, but there's something endearing about the deadly seriousness of the characters and the inclusion of ritual elements that feel authentically researched. It's also a great mixture of supernatural set pieces and suspense building that still holds up in many ways and delivers a fine trip into the occult.
Nicholas, the Duc de Richleau and his country club friends have to battle the powers of darkness when their friend Simon falls in with a suspicious astronomy club. He's been out of touch for months and has bought a new house with an observatory decked out with satanic motifs. They're the kind of people that own rural estates and private aircraft, so I guess he was out looking for new thrills. Nicholas is not at all impressed by the members who have arrived for a secret meeting, and things start to look shady when he finds evidence of what they are planning. The occult leader Mocata, played with sinister charisma by Charles Gray has his hypnotist eyes on Simon as well as Tanith, another young recruit to their inner circle. His scheme is not exactly clear but it's probably something to do with pointy daggers, black candles and chalices full of blood.
There are a lot of sequences that soon shake any scepticism from the other characters, though some have aged less gracefully than others. Plenty of strange spirits and entities are summoned including what seems to be a genie of some kind with rectangular pupils and a series of visions that are sent to frighten Nicholas and friends as they hide from the cult over night. Even the devil himself drops by to say hello during a debauched satanic party. The practical elements work well enough with goat head prosthetics and glowing pentagram floor decorations, but the optical effects were probably ropey when this was new. At least most of them are quick and efficient, although a charging horse stands out as being badly looped and repeated in reverse motion. But it's all of its time, and the newer 'restored' version is far more offensive.
However in terms of an atmospheric mystery plot things are pretty satisfying. The race to stop the circle before the night of their satanic baptism ceremony takes plenty of twists and turns that include seances, psychic powers and even a period car chase to show Mocata's reach. They also have the visual elements that mark the best of Hammer with purple robes and burning fire lights. The script is full of dry retorts and discussions about impending doom, although the true motivations of the inner circle are never explored with any detail. The source material has been trimmed to keep the pacing brisk, and the moments that discuss power being attained through innocent sacrifice is left out. Lee and Gray are great figures leading each side; the uptight but well versed aristocrat facing the grinning magician. It's worth seeing just for these two, but in general this is a good example of bringing all these different elements together.