The title of "Booby Trap" director Herbert Cass' horror movie "Blood of the Vampire" is misleading. Actually, no traditional vampires with fangs appear in this atmospheric chiller about a mad 18th century Transylvanian scientist performing illegal medical procedures. A man who embarks on bizarre medical experiments, Doctor Callistratus (Donald Wolfit of "Becket") pays the ultimate price for his perfidy with death. Not only do righteous, good people put him to death, but they also have a powerfully built chap who sinks an iron stake into Callistratus' body and then hammer it through his corpse. Meanwhile, the mad scientist's loyal right-hand man, a crippled, deformed hunchback with one drooping eye hanging out of his face, Carl (Victor Maddern of "Chitty Chitty Bang Bang"), takes Callistratus' body to another unethical doctor who performs open heart surgery and brings Callistratus back to life.
Mind you, Callistratus had been accused of being a vampire because he conducted experiments on his doomed patients to learn more about their blood and why some blood rejects other blood. British horror writer Jimmy Sangster has conjured up an interesting Gothic melodrama, but the absence of a vampire undercuts the narrative. You keep waiting for the notorious supernatural figure to show up but it never does. Doctor Callistratus manages to obtain a post as a prison warden so he can experiment with a variety of bodies. His downfall comes about when another doctor, Dr. John Pierre (Vincent Ball of "Where Eagles Dare") is put on trial for the unorthodox medical procedure of transfusing blood and sentenced to life in prison. It turns out that one of Pierre's witnesses, who sent him testimony by mail, didn't write the letter that would have cleared Pierre. Instead, another man, Monsieur Auron (Bryan Coleman) intercepted the letter and rewrote it. Rather than being confined on Campbell Island, our wrongly charged protagonist—Dr. Pierre—winds up in another prison; Callistratus runs the prison where Pierre is incarcerated and he uses Pierre to help him in his diabolical experiments. Callistratus is searching for a way to avoid constant blood transfusions because the cells in his blood are at war with each other. Eventually, Auron warns Callistratus that the alarming number of deaths occurring at his prison is bothering the authorities.
Just when things for Callistratus couldn't get worse, he hires a new cleaning lady, Madeleine Duval (Barbara Shelley of "Dracula: Prince of Darkness"), to work for him. What Callistratus doesn't know is that Duval is Pierre's wife. She got Pierre defense witness who wrote the damaging letter to come forth and report that his testimony had been tamper with and the court had changed its ruling and cleared Pierre of all foul play. Callistratus responded by reporting that Pierre had died during a prison break and he is taken for his word. Duval shows up incognito to save her husband, but she runs into Auron who wants to rape her. Carl attacks Auron and Callistratus intervenes. He winds up killing Auron because the man tells him that he will turn him into the authorities. At the same time, the evil Callistratus decides to use Duval in one of his unearthly experiments. Pierre manages to escape and thwart Callistratus.
No, the make-up for the murderous hunchback lacks verisimilitude, but it adds a grotesque sense of cheesiness to "Blood of the Vampire." Everything else looks good, especially the sets. "Blood of the Vampires" relies on a formulaic, melodramatic plot. The performances are good, especially Wolfit as the fiendish Callistratus, but the far-fetched action and the absence of a vampire undercut the action.