Minneapolis, Minnesota. On one rainy evening a customer knocks on a nurse's door. The nurse, a black woman, is concerned that even though this is the first time she has treated this customer, she feels that she has met him before. The woman does not have time to remember, as a she is hit with a hammer precisely and vigorously to the nape of her neck, which stuns and paralyzes her. By now immobile, but perfectly conscious, she sees a slipknot of steel encircle her neck. A few seconds after the head of the woman rolls on the floor in a puddle of blood. The murderer puts the head in a purse of black leather, and takes off in the rain. By now it is morning and while David, a young artist for a television broadcasting station, is driving to his job, he sees a girl trying to jump off of a bridge with a clear suicidal intention. The young man hastens in help and is able to dissuade the girl from her insane gesture. The young woman is very thin, suffering, lost, with her arms covered with holes from syringes, modestly dressed but she wears on her wrist a very handsome gold bracelet. David convinces her to go with him into a coffee house; explaining to her that he was also once a drug addict, and he invites her to confide in him. The girl is annoyed, then notices that two police officers are spying from outside the window of the cafe. Pretending to go to the bathroom, she runs away to a back exit, but the agents stop her. They have recognized her as Aura Petrusco , a minor of Romanian origin, who ran away from a hospital where she was in care. David meanwhile, has not noticed, until the moment he attempts to pay the bill and can't find his wallet. Aura is brought again to her parents' home. Adriana, the mother, a famous occultist, reproaches the daughter bitterly for having escaped from her care. The authoritarian woman orders her subdued husband Stefan to confine Aura to her room. Night falls on the Petrusco home and guests start to arrive to participate in a seance. While a terrible storm rages, the doctor Judd also arrives, the physician who took care of Aura, a man impassioned with mysterious sciences. The guests join hands on the table while Adriana evokes the spirit of contact, Nicholas, but the medium warns that she has entered contact with another spirit, that of a woman as recently dead who persues her executioner. She reveals to have been fiercely beheaded and discloses that the murderer is present in the room. Suddenly a tree branch, folded up from the wind, breaks the glass of the window and an icy puff of wind extinguishes all the candles. Adriana, as if possessed, runs to the outside of the house pursued by Stefan. Aura, who has seen her mother from her window run away in the night, under the strong rain, begins to search for her parents. Unequivocal traces carry the poor Stefan to make a horrible discovery: the headless body of his wife. Immediately a slipknot of steel encircles his the neck cutting it. Comes Aura, just in time to see the murderer run away with two heads hoisted as if a grisly trophy in front of the face. When the police arrive, for fear of being brought again to the hospital with the doctor Judd, she runs to her escape.
The day after, David receives a phone call from Aura. She has been able to track him down from the documents found in his stolen wallet. After the girl has told him her history, David decides to help her. Aura, upset, is obsessed by a question: who has killed her parents? In another district of the city a child observes from his bed the strange movements in a near house and tells his mother the he has seen the head, only the head, of a black woman in the window. "Imagination!" her mother replies, and tells him to go to sleep. The affectionate mom, certainly would not ever suspect that the calm palace next door is the shelter of the assassin, the "Headhunter". David understands, observing the daily behaviors of Aura, that the girl is anorexic, a serious form of illness born from the refusal of food. The presence of Aura at his home, and above all the attention and the cares of David, instigate the jealousy of Grace, the cold, determined anchor-woman who entertains a passionate relationship with the young man. Grace turns in the girl, the sought-after witness of the crime that took her parents. The district attorneyt, after having interrogated her, redelivers Aura to the cares of the doctor Judd. The physician forces Aura to ingest the juice of a hallucinogenic berry that has the ability to remove all the impediments that stop the memories from coming forth. Aura relives the moment in which she has suffered the trauma finally: a morning, returning home, she had seen the mother lie together with the doctor Judd. To her awakening the girl finds herself strapped into a hospital bed, while the nurse Halina Walckmann tries to repeatedly inject her with a needle. In the hospital arrives also the "Headhunter." As soon as she has gotten out of girl's room, the nurse is stricken and beheaded. Aura, who has been able to free herself, finds David again and they together escape. The following day, the two young people try to reflect on the killing of the nurse and they begin to investigate her past. During the search, they find a photo that brings together a connection. The group in the photo is under the coat of arms of the Saint Bartholomey Hospital. Two of those women are not anything else other than the first two victims of the "Headhunter." David understands that the murderer pursues a plan, perhaps as revenge certainly for any mysterious event that happened in that hospital. From a note on the back of the photo, David is able to individualize the two other people that appear in the photo: Linda Quick, a nurse, and a physician. The young man is able to track down Quick. The woman, terrorized, mistakes him for the murderer and she escapes. The escape however ends brutally: in a hotel room Linda Quick is mutilated. Worse is the fate of the male physician of the photo, his life in downfall after the terrible accident that the four nurses witnessed. The "Headhunter" cuts off his head using a freight elevator like an ax. The doctor Judd, enters furtively into David's apartment, trying to abduct Aura. David wakes up and between the two gets into a furious quarrel, interrupted by the sirens of a police car. Judd runs away with his old Cadillac but gets into an accident and is mortally wounded. From the collision the trunk has opened and has revealed four human heads. The case seems resolved. Judd is the guilty one. David returns home and finds a note from Aura that says: "I've gone to be with my mother"!. The young man goes toward the shores of the lake and finds the suit of Aura. He desperately plunges into the dark waters to search for the girl, but in vain is each of his attempts. Time has passed and David, torn to pieces from the sense of guilt he has from not being able to save Aura, vagabond of the city, stunned from drugs, is shocked to see the arm of a woman with a gold bracelet precisely like Aura's. He follows the woman and sees her enter a white house, then, spying from a window, glimpses a slender figure of a girl. She is Aura, she is alive! David rushes to the house, but a violent hit to the nape stuns him. When he recovers, he is in a wine cellar, chained, but next to Aura. The young man is joyous with all of his love, but the door of the impromptu jail opens wide and there appears the murderous truth. It is Adriana, the mother of Aura. The mystery is disclosed. Many years ago, while the woman was giving birth, a terrible storm removed the electricity from the room in the clinic while the physician was grasping the scalpel; the newborn came, horribly beheaded. Nicholas, the spirit called by the medium, was none other than the dead child that avenged its beheading, in the days of torrential rain, those responsible for the accident. The murderer that Aura had seen run away was that of her mother, who held up the decapitated head of her husband. Adriana wants to free herself of David, by now a dangerous witness: only from the timely intervention of the young neighbor, who tightens on the neck of the woman the same slipknot she used to kill her victims, the two young people in love are saved.
