Captain Harry Spalding (Ray Barrett) has recently suffered some bad news when he was told of the death of his brother, Charles (David Baron). What he was not told was the manner of his demise, which involved him being bitten on the neck by a mysterious creature and dying painfully but swiftly from its poison. Harry decides to move into his brother's Cornish cottage with his wife Valerie (Jennifer Daniel), partly to have somewhere to live, and partly to find out more about the puzzle of Charles, but they are to be greeted with a frosty reception from the locals...
If you have seen director John Gilling's Plague of the Zombies and are watching this and thinking, hello, looks familiar, there's a good reason for that (this also works the other way around as well). That being, they were both shot on the same sets and back to back in a spot of costcutting; you might also find the plot here somewhat similar to the earlier Hammer horror The Gorgon, although instead of Greek myths, it's Eastern mysticism which concerns us here. While it never whips up into the frenzy it keeps threatening to do, it's still an interesting addition to this studio's line of non-Frankenstein and Dracula monsters.
It does get close to a build up of delirium in some sequences, but it's a little too staid in its worries to really let loose. After an introduction that sees poor old Charles kick the bucket after wandering around for a couple of minutes, face turning black and foaming at the mouth of course, we're stuck with some pretty colourless leads. It's not the actors' playing that is at fault, it's the humourless script by Anthony Hinds, although there is an unintentional laugh near the start when Harry clears the village pub not once but twice merely by striding in and announcing himself.
It's the character actors who steal the show, then, with Michael Ripper and John Laurie having the most fun with their roles. Ripper is the local pub owner who takes a kindly but insistent interest in the recent death, helping out Harry in his investigations. Also assisting is Laurie's Mad Peter, the resident eccentric as his nickname implies, who hears strange noises on the moors and takes advantage of the Spaldings' offer of dinner: plenty of opportunities for eye rolling there. Sadly, in spite of Laurie introducing a spark into the proceedings, he turns out to be the next victim.
So what is behind the killings? It's not too hard to figure out with the most sinister happenings occuring at the mansion of local doctor - of theology - Franklyn (Noel Willman), who lives there with his daughter Anna (Jacqueline Pearce, best known to Brits from her role in gloomy science fiction serial Blake's 7 the next decade) and his Malayan manservant (Marne Maitland). There's a potent mixture of colonial guilt and unhealthy overprotectiveness in the personality of Franklyn that leads to tragedy and more, and this hangs heavily over the characters, with lonely, sitar-playing Anna suffering more than most - apart from those who get chomped in the neck, of course. It all ends far too predictably, as even by this time the finale here was old hat but The Reptile proved high quality enough for a middle-ranking Hammer effort. Music by Don Banks.