In 1885 London, the famous Professor Bernard Hichcock has created a new method of anaesthesia and has become rightly famous for it. A renowned, brilliant, and humane surgeon, he also happens to be a necrophiliac who enjoys sexual games with his beautiful and very willing wife, Margaretha. The games include slowing his wife's pulse with this anaesthetic so that she seems corpse-like. Sadly, one night, he injects her with too much and she dies in his arms. Devastated and traumatized, he resigns from his position and leaves England, the reason for his wife's death, of course, never publicly revealed. He returns twelve years later, remarried to Cynthia. His housekeeper, Martha, who was loyal to him and Margaretha, and even a devilishly delighted romantic co-conspirator in preparing the funeral-parlor-like room for their sex games, makes it clear that she views his remarriage as a betrayal: she treats Cynthia coldly and Bernard with scornful glances and without the familial devotion she showed before Margaretha's death. Cynthia starts to hear noises and a woman's threatening voice, and while Bernard initially dismisses her worries as paranoia, eventually discovers that Margaretha had not died but rather had been unnaturally aged and driven insane by the overdose and premature burial; apparently, Martha had saved her and has looked after her during Bernard's absence. Even in her ravaged condition, Bernard is still deeply in love with Margaretha, and conspires to murder Cynthia so he can use her blood in medical efforts to restore his wife's health and beauty. Needless to say, Bernard is thwarted, he and Margaretha dying in a conflagration at the end, while Cynthia is saved by Bernard's handsome young assistant. The subject matter of the film was revolutionary for its day and indeed for any period. The viewer is also asked to make some complex emotional and moral decisions: the real, and tragic, love story of the film is that of Bernard and Margaretha, but we must accept that his original error can only be undone at the expense of his dreary second wife's life. It is a brilliant film, certainly among the best Italian horror films and probably among the best horror films of any national origin. Most notably, the famous Barbara Steele is little more than a cardboard stock character as Cynthia. It is probably her least important role.