Sir Julian Markham (Vincent Price) owns a large plantation in Africa, but has vowed never to return there after what happened to his brother Edward (Alister Williamson). The last time they were out there, a tribe captured Edward and subjected to a horrific rite which left him disfigured and on the verge of going completely insane. Now he lives chained up in an upstairs room in Julian's mansion house back in England, but knows he has to contact African witch doctor N'Galo (Harry Baird) if this curse is to be lifted...
Actually, the people working on The Oblong Box must have been wondering if there was a curse on the film, never mind the characters, because this was the horror that Michael Reeves was supposed to make before he tragically died, leaving behind a legacy of a handful of promising works, although what kind of wonders he could have made out of this material remains to be seen. Not only that, but a few days into shooting the writer, Lawrence Huntington, died, which surely set the production thinking that dark forces were afoot to sabotage the film.
Well, maybe they weren't so superstitious after all, but when the movie was released to fair reviews and middling business it was clear that it was very much in the shadow of the Roger Corman Edgar Allan Poe chillers that had preceded it. Although taken from similar source material, this was a far less stylish effort, almost rough-hewn in its appearance so that there was little to attract the eye here. In a way this suited the grim atmosphere of a tale which relied heavily on the characters' guilt to propel it, with Julian regretful that he was the one meant to endure the curse that his brother now suffers from.
There is a dodgy geezer called Trench (Peter Arne) who is facilitating the meeting between Edward and N'Galo in the hope he will get his hands on some of that fortune, and he devises a method of freeing Edward from his chains: pretend he's dead. With Julian believing him killed, he makes preparations for the burial, and the body is sealed in a coffin, even though it is really in a drug-induced coma. To complicate matters, somewhat needlessly it has to be said, Julian wants the body to be viewed and orders Trench to find a replacement corpse to stand in (or lie in, more accurately).