A man and wife are terrorized by Mad Scientist Dr. Callistratus who was executed but has returned to life with a heart transplant. Along with his crippled assistant Carl, the 'anemic' Mad Scientist, believed to be a vampire, conducts blood deficiency research on the inmates of a prison hospital for the criminally insane to sustain his return to life.
Barbara Shelley (born 15 August 1933) is an English film and television actress.
She is now retired, but was at her busiest in the late 1950s (Blood of the Vampire) and 1960s when she became Hammer Horror's number one female star, with The Gorgon (1964), Dracula, Prince of Darkness (1966), Rasputin, the Mad Monk (1966), and Quatermass and the Pit (1967) among her credits. Although she is known as a scream queen, in fact her most famous scream (in the aforementioned Dracula film) was dubbed by co-star Suzan Farmer.
She also appeared in Village of the Damned (1960) and in the 1984 Doctor Who serial Planet of Fire.
In 2010, writer and actor Mark Gatiss interviewed Shelley about her career at Hammer Films for his BBC documentary series A History of Horror