It is well known that the best way to prevent a vampire from returning from the dead to drink the blood of the living is to drive a stake through its heart, and so it is tonight when the body of the recently deceased Dr Callistratus (Donald Wolfit) has that action performed upon it, the locals believing he was a supernatural menace when he was alive. But he had an ally in the deformed Carl (Victor Maddern) who fetches the drunken local doctor to perform a heart transplant on the body, which he does, then is murdered by Carl to cover up the surgery...
But actually Callistratus is not a vampire in the traditional sense, for in spite of being raised from the dead in the first few minutes he didn't go around biting jugular veins to slake his thirst, this was a more scientific approach we were seeing. You could observe it was a cross between the Frankenstein and Dracula movies with which the British studio Hammer made their name, and that was no coincidence for those efforts shared a writer in Jimmy Sangster, who was on script duties here as well. He had just enjoyed a huge international hit with Curse of Frankenstein which is likely why Blood of the Vampire more closely resembles that.
Rather than the Hammer Dracula which was shot almost simultaneously with this, hailing from producer Monty Berman, a man who prompted a few Hammer aping movies for a brief period, in some territories doing even better than them thanks to his habit of filming stronger versions for overseas, the British version being rather toned down in light of the harsher censorship the country was labouring under at the time. Certainly here the purpose appeared to have been to craft something as lurid, if not more, than the Frankenstein picture, and you can see its almost slavish methods of trying to one up that rival in practically every other scene.
For the lead villain they hired Wolfit, a reliable old barnstormer of the theatre who made occasional big screen appearances; his reputation was as a ham, which naturally was precisely what a horror such as this needed and didn't they know it. Although offscreen for the best part of twenty minutes as the plot is established, when he did show up he made his impression as a lipsmacking villain of the Tod Slaughter school, indeed if Slaughter had survived you could envisage him taking just this type of role. That setting up sees unfairly accused doctor John Pierre (Vincent Ball) lose his court case and sent to an asylum.