Santos Alcocer’s Cauldron of Blood (1970) (AKA Blind Man’s Bluff) was filmed in 1967, but languished on the shelf until its release three years later (to little fanfare, despite its potential marketing as one of horror icon Boris Karloff`s last films). Where Curse of the Crimson Altar (1968) was a low-rent knock off of Black Sunday (1960), Cauldron is an equally low-rent rip of Mystery of the Wax Museum (1933) and House of Wax (1953).
Karloff co-stars with veteran Viveca Lindfors (who is possibly best know as the queen who aroused Errol Flynn in 1948’s The Adventures of Don Juan). Cauldron was shot almost entirely in Spain, and is remembered only as an accidental idiosyncrasy from late in Karloff’s career.
Cauldron of Blood is not a good film, but it is a queer film, quite unlike anything else in the Karloff cannon, which may be explained by the fact that Karloff was not even the preferred choice for the role of the blind sculptor Badulescu. Producer Robert D. Weinbach had wanted Claude Rains, but Karloff was brought into the project after Rains was found to be terminally ill (Rains died during the pre-production stage of the film). Karloff is not even top-billed, which was an extreme and curious rarity.