In the Swiss Alps, three British students are climbing one of the mountains near the region of Trollenberg where a strange mist has settled. One of the party has ascended ahead of the other two and is finding it difficult to see anything in that fog close to the summit, but his friends are still audible to him, so he continues the conversation. Yet the talk turns sinister when he claims he can make out something in the gloom, then suddenly lets out a scream and falls over the side. The companions have hold of the rope and pull him up - until they notice his head has been torn clean off.
The Trollenberg Terror was one of many productions whose origins could be found on television, British television in this case, attempting to emulate the success Hammer had enjoyed with their adaptations of the BBC's Quatermass serials, and in its way it might not have set the box office alight and gone down in history as one of the great sci-fi movies, but it did make its mark. Future horror talent like John Carpenter and Joe Dante referenced the shorter American cut of the film under the name of The Crawling Eye in their work, and Stephen King sneaked in an appearance of the titular monster to his epic tome It.
As King observed in his overview Danse Macabre, nobody ever made a film called The Crawling Ear, and there was something about the essential squishiness of the giant creatures here which went beyond their somewhat shoddy effects and tapped into a sort of half disgust, half fascination, even if they might have prompted a few chortles when they slid towards the cast, occasionally snagging a few with their tentacles. Though what they were doing with the heads they harvested was a mystery - one shows up in a rucksack later on to give someone a fright - with telepathy a major factor when a couple of sisters in a mindreading act pass through Trollenberg.
The elder, Sarah Pilgrim (Jennifer Jayne), acts as the guardian of the "sensitive" younger, Anne (Janet Munro, on the brink of minor Disney stardom), but the latter insists they stop at the town for reasons unknown. At first, anyway, as it soon becomes clear Anne has a link to the inhabitants of the cloud which is gradually expanding down the mountain, very gradually, with a lot of talk before the riproaring last act finally settles upon us. Still, if you got restless waiting for the fireworks (not a problem exclusive to this, as the contemporary likes of Fiend without a Face had the same issues) there was always Warren Mitchell demonstrating yet another accent to distract you.
Mitchell played the scientist role, he and his team of boffins holed up in a reinforced mountain observatory where he can survey the scenery and investigate the weather, including that strange cloud, but he wasn't the hero. That was Forrest Tucker as Alan Brooks, an imported American star taking control as such characters were wont to do, either with his know-how or latterly his improvised Molotov cocktails, which are the only thing able to stop the aliens aside from a passing bomber courtesy of the military. Marking this out against some of the American sci-fi thrillers was how bloodthirsty it was what with those bonces parting company with their owners, and we got a look at a headless body or two, complete with gore, to live up to the British X Certificate it was aiming for. Also worth looking out for was the world's fattest mountaineer, but don't let him take anything away from the fun of the special effects extravaganza as those huge, bulbous, thickly veined whatever-they-weres caused chaos. Music by Stanley Black.