Director Vernon Sewell never generates anything but the most routine of suspense. Any atmosphere during the drug hallucination sequences, for instance, is considerably undone by such laughable sights as a body-builder in tights wearing what is clearly a motorcycle helmet with studs and a pair of antlers glued on it. The plot is weak, with the action consisting of much skulking around the house and a series of clumsily unveiled clues. The title is of little relevance – to be strictly fastidious, the story is not about the curse of the crimson altar but the curse of the green-skinned witch. Like many (particularly British) films of the late 1960s, Curse of the Crimson Altar is quick to draw a connection between then youth culture, drugs and Satanism – the opening quotation boldly connects drug taking with Satanism. However, apart from a brief orgy sequence as Mark Eden turns up at the manor, this is a promise that is never fulfilled (and the youth orgy angle raised by the credits is a sensationalistic cheat as it the lord of the manor, not his wayward niece, who is involved in the occult).

The film also manages to criminally waste a fine genre line-up. Cult Italian-horror queen Barbara Steele appears only painted in green and without any lines, while Michael Gough makes an appearance as a mad butler uttering cryptic portents then later turns up dead in a coffin without any explanation. Christopher Lee has been through it all before and at least holds the dreary proceedings together by maintaining a consummate professionalism. Unfortunately, the mere fact that it is Christopher Lee tends to mitigate against the mystery that has been built up – Lee being perfectly polite and denying any knowledge of the missing person, at the same time as evidence to the person’s having been there continues to mount, only acts like a giant neon arrow that points in his direction.

The person that does best out of the affair is 82-year-old Boris Karloff who, despite being wheelchair-ridden and badly showing his age, manages to convey some sinister threat. The moment he invites Mark Eden to come and see his collection to which Eden innocently asks “What sort of collection?” and Karloff, with a sweet smile, answers “Instruments of torture,” is great (even if the mere tableful of instruments later presented heavily belies the moment). The greatest distinction Curse of the Crimson Altar had is in being Boris Karloff’s last film (apart from four films made in Mexico films that never received distribution until on video in the 1980s). Karloff died of pneumonia, which is reputedly something that he caught during the film’s location shooting in the draughty manor.

Curse of the Crimson Altar was one of the films made by Vernon Sewell, a minor director in the heyday of English horror cinema. Vernon Sewell also made:- The Medium (1934), Latin Quarter (1945), The Ghosts of Berkeley Square (1947), Ghost Ship (1952), House of Mystery (1960) and The Blood Beast Terror (1968).