Boris Karloff plays Franz Badulescu, a famous sculptor and who has been blind since his wife, Tania (Viveca Lindfors) tried to murder him for his fortune. Claude Marchand (Jean-Pierre Aumont) has come to the Spanish village of Pinderera to interview Badulescu for a travel magazine. Not surprisingly, Tania and her lover (Milo Quesada) are making a second attempt on Badulescu's life, but they kill a couple of other people first, apparently so they can hide the bodies the sculptor's statues; this looks good but makes no sense. I also have no idea why the evil couple waits until there is a visitor to try something as difficult as killing a blind man... "Cauldron of Blood," originally titled "Blind Man's Bluff" and known as "El Coleccionista de Cadaveres" in Mexico, is one of Boris Karloff's final films, released after this his death. Ironically, although Karloff was ill with emphysema, he got this role because Claude Reins was too ill to accept the part. Certainly not as bad as the final quartet of cheap horror films Karloff made for a Mexican producer in 1968, "Cauldron of Blood" is still a cheesy movie. I would recommend you check out one of Karloff's lesser known horror films from the 1930s like "The Black Room" instead.
I've seen several conflicting accounts of the plot for this film. As I see it it's a straightforward "wife plus lover plot to kill wealthy ageing husband to get his money" vehicle but not until he's completed his current commissioned work. Around this are woven the horror elements including the use of real skeletons as armatures for Karloff's sculptures (presumably necessary to help him continue to working since becoming blinded as the result of an earlier failed murder attempt?). It's a typical 60's cheesy euro technicolour horror feature but is visually very attractive and has an interesting score and a nice opening title sequence making it better than many films of this genre. The print quality is very good plus there's a bonus Karloff serial episode.
I was encouraged to view this since a couple of reviews were very positive. Upon initial viewing, I was soon disappointed. It looked and sounded terribly dated, and the picture quality was worse than a transfer from a Super 8 film stock. After about 15 minutes struggling with this film, I gave up. Quite honestly, I don't think I needed to waste any more time. Now, the extra; an episode of Colonel March starring Boris Karloff was worth seeing. Running for about 22 minutes, it starred a few well known actors from the '50s and '60s; Anton Diffring; Eric Pohlmann and Arthur Hill. Worth a look, but the main feature was a big let-down.