Romania, the 19th Century. Dr. Eswai (Giacomo Rossi-Stuart) arrives in a secluded Transylvanian village where he checks into a local inn and meets with Inspector Kruger (Piero Lulli) the local constable who is investigating the death of a young girl employed as a maid at Villa Graps. The inspector has summoned Dr. Eswai to the village to perform an autopsy on the girl, much to the dismay of the locals. With the assistance of Monica (Erika Blanc), a nurse who just recently returned to the village for the first time since she was a child, Dr. Eswai carries out the autopsy. They make an incredible discovery: a gold coin imbedded in the dead girls heart. Monica reveals that this is consistent with a local superstion. Only with money in the heart, can one who meets a violent death ever rest in peace, says Monica. Following the autopsy, Eswai assists Monica back to her home. He is then attacked by a small mob of several villagers who swear vengeance on him for profaning the dead girls body. Only the sudden appearance of a mysterious woman, clad in black, saves the doctor from being beaten to death. But before he can thank her, she disappears into the fog.Back at the inn, Eswai receives a note instructing him to join Inspector Kruger at Villa Graps. When the doctor asks Nadine (Micaela Esdra), the innkeepers little girl, to direct him to the villa, she tells him to stay away from it. But Eswai leaves for the villa anyway, and when Nadine goes to lock the front door behind him, she is terrified by the sight of a ghostly little girl, peering in at her through the window. Nadine tells her parents what she saw, and they send out for Ruth (Fabienne Dali), a local sorceress who has the ability to ward off evil spirits. When she arrives, Ruth is the same black-clad woman who had earlier rescued Dr. Eswai from the villagers. Ruth says several prayers over the girl before giving her a leech-vine to wear around her waist. Ruth says that as long as she wears this, Nadine will be safe. At the villa, Eswai is confronted by Baroness Graps (Giana Vivaldi). Shut away from the outside world in a morbid environment dominated by black lace curtains and remnant of the past, the Baroness appears haunted by supernatural apparitions. She curtly tells Eswai that she never receives guests, denies any knowledge of Inspector Krugers whereabouts, and eventually slam the parlor door in his face. The doctor then sees a ghostly, white-clad girl, who identifies herself as Melissa (Valerio Valeri). He attempts to talk to her, refusing to believe the superstitions of the villagers, but she walks around a corner and disappears. Without the inspector to assist him, Eswai makes his way back to the inn.Meanwhile, Monica is plague by a nightmare in which she is menaced by a chillingly innocent-looking doll. When she wakes up, she finds the exact same doll laying at her feet. She flees from her house and runs into the doctor on the street. Together they return to the inn. Monica confesses her fears to Eswai that she may be cursed. Eswai assures her that these strange occurrences are the products of fear and supersition, not of the supernatural. While Monica is shown to a room by the innkeeper, Eswai is distracted by moans coming from Nadines room. He goes in and sees the little girl withering about in bed, apparently suffering from a fever. Pulling back the sheets, he finds the leech-vine. Though her mother assures him that it is only for her own good, the doctor takes it off her. His care for the girl does no good, for later that night the ghost of Melissa reappears, compelling the girl to commit suicide.Eswai and Monica continue to delve into the mysterious of the death and of the ghostly little girl. A strange light appears in the nearby cemetery, and an investigation results in the discovery of Inspector Kruger, who has been shot through the head at close range. Eswai brings this latest crime to the attention of the Karl the Burgomaster (Max Lawrence), who reluctantly agrees to shed some light on the situation. The Burgomaster tells them that several years ago, Baroness Graps placed a curse on the whole town when her young daughter, Melissa, was trampled to death by the drunken townspeople during a village festival. Now the ghost of Melissa haunts the guilt-ridden people, and all who make mention of the Baroness or her child soon bleed to death under mysterious circumstances. The Burgomaster also reveals that to Monica that she is actually the dead girl's sister. He offers to go back to his residence to offer them proof. But when the Burgomaster goes back to his house and searches his attic for Monica's birth certificate, he too is driven to suicide when Melissa appears in the attic.Ewai and Monica go to the villa where Monica is warmly greeted by the Baroness with open arms. She confirms the Burgomisters story and explains how Monica was smuggled out the villa by the servants when she was just a child soon after Melissas death. When Monica suddenly disappears, Eswai searches for her in various rooms. Eswai follows her screams before catching sight of another man running through a series of rooms lined with red curtains. Eswai chases this person though apparently the same red curtained room over and over, getting closer to his target at every pass. Eventually, Eswai catches the man and when he turns around, the doctor is shocked to see his mirror image. A second later the doppelganger figure is gone, a hallucination conjured up by the supernatural forces of the villa. The doctor, frightened and disoriented, backs into a cobweb covered fresco on the wall which depicts the outside of the villa. As the image pulls back, he appears to be a fly caught in a web. He is no longer indoors, and the fresco is now the actually outside of the villa, some distance in the background. Eswai shakes loose of the web, and faints.When he wakes up a little later, he is in Ruth's care. To the people of the village, Ruth, with he magic spells an d charms, is the only doctor of any use. It is the ultimate irony that she should be administering to the needs of the man of science who scoffs at superstatiion. Further compounding the irony is that this is the second time she has rescued the doctor.At this point, convention logic is useless to the doctor. The norms of the advanced society where he comes from, and comes to represent to the backwards villagers, are totally dissolved. With the deaths of the Burgomaster and the police inspector, social order is diminished in the village. The only authority figure to carry any weight are the Baroness, her ghostly avenger, and the sorceress whose spells prove to have more power than any medicine the doctor has. Eswai forgets his preconceived notions and is willing to accept the presence of the supernatural.Eswai returns to the villa to find Monica, but Ruth also tags along and comes face to face with the Baroness at last. Spurred on the by death of the Burgomaster, her lover, Ruth attacks the Baroness, but who gets the upper hand and stabs Ruth in the chest with a fireplace poker. Ignoring the seriousness of her wounds, Ruth strangles the Baroness to death with her bare hands before she expires too. With the Baroness death, a force flows out and the ghost of Melissa, on the verge of having Eswai commit suicide himself, disappears having been put to rest at last. Eswai and Monica realize that they are now free to leave the village to start their lives over elsewhere.