Profondo rosso
Tags: psychological, gothic, murder, paranormal, cult, horror, violence, atmospheric, flashback, insanity, psychedelic, humor, suspenseful, sadist

Plot synopsis:
In the opening shot, while a child's song is playing in the background, a scream is heard, a unknown bloody knife is thrown to the floor, and a youngsters feet stand by the knife.Marcus Daly (David Hemmings) a British jazz pianist is conducting some music and tells the musicions that the music must be more perfect.At the same time, Helga Ulmann (Macha Meril) is at a lecture with Professor Giordani (Glauco Mauri) and Mario Bardi. During the presentation, Helga reacts violently to a premonition of a "twisted mind" and she says "you have killed, and you will kill again!" Helga also mentions a singing child. Someone in the audience gets up a leaves. Later, Helga tells Giordani that she may know who the killer is and that she will write it down and tell him tomorrow.At Helga's apartment, she is on the phone with her German publisher when she hangs up after hearing a children's song being played in the background. A minute later, the front doorbell rings. Helga gets up to answer it when she has a bad psychic vibe and backs away from the door. Just then the door bursts open and the killer (unseen except for wearing a brown raincoat and black leather gloves) bursts in and attacks her with a meat cleaver, stabbing her several times. Leaving her for dead, the killer then takes Helga's notes and begins to look through her papers while Helga tries crawling away.Down in the square below Helga's apartment, Marcus is talking with his constantly inebriated friend Carlo (Gabriele Lavia). Shorly after Carlo leaves, Marcus looks up and sees a bloody Helga crash through her apartment window. Marcus runs up to Helga's apartment, helps her dead body out of the broken window, and sees a person in a brown raincoat running away through the square. A little later, the police arrive and question Marcus about witnessing the killing. Marcus feels that something from the apartment is missing but cannot put his finger on what it is. Just then Gianna Brezzi (Daria Nicolodi) a fiesty photojournalist, enters the apartment, but is told to stay away by the lead detective. After his interogation, Marcus speaks with a drunk Carlo again in the square where he thinks he remembers a paint when initially entering Helga's apartment, but later was not able to locate it.At Helga's funeral, Gianna suggests that she and Marcus work together to find the killer on their own. Marcus sarcasticly thanks her for printing his name in the local newspaper and declaring him a witness which would make it easier for the killer to come after him. After discussing Helga's premonition with Giordani and Mario, and seeing Carlo to talk about the mysterious missing painting, Marcus goes to his aparment to compose some music. He soon hears the children's song, followed by the sounds of his door creaking open. As the phone rings, Marcus jumps up and pulls the door to his room shut, just when the unseen killer attacks. The killer leaves and whispers threats to him before leaving.The next day, Marcus goes to a record store and after going through albums of children's music, finds the song he heard. Mario tells him a folktake involving a haunted house in which a singing child is heard, followed by the shreiking of someone being murdered.In investigating the source of the music tune, the search leads Marcus to a novel which was written by a cerain Amanda Righetti (Giuliana Calandra), titled 'House of the Screaming Child' which describes a long-ago murder. In attempting to find Amanda Righetti to talk to her about her book, the unseen killer arrives at Righetti's villa first and murders her. The female author is stabbed in the spine, then dragged into a bathroom and drowned in a bath filled with scaldingly hot water. But Righetti manages to write a message on the wall of the steam-filled bathroom before expiring. Marcus finds the body, but aware that the police will think he did it, leaves the area without calling anyone.Marcus removes a photo of the supposed haunted house from the novel to help him in his search for the mysterious house. The photograph shows some exotic palm trees on the house grounds. Marcus tracks down the greenhouse owner who admits to selling a dozen or more Canary Island palms to that house, and procures the house's address from past records. Driving around, Marcus finally locates the house and learns from the caretaker who claims that no one have lived in the house before 1963 when the previous owner was killed. Marcus looks around and discovers a children's drawing on a wall long plastered over of a little boy holding a unknown bloody knife next to a murdered man.Meanwhile, Giordani investigates the Righetti murder scene after the police collect the body and leave, and on a hunch, turns on the hot water in the bathroom and sees part of the message left on the wall by murder victim. When Giordani returns to his office that night to investigate more, the unseen killer breaks in and kills him too - first by bashing his face against his desk, and then stabbing him through the neck.When Marcus learns of Giordani's murder, he makes plans to leave town but then discovers the clue that he overlooked in the photo of the deserted house: a window on one of the walls is missing. Marcus returns to the house after dark and after unsuccessfully trying to bash in the wall where the window was, which leads to him nearly falling off the scaffolding, he enters the house and using a pickaxe, bashes down an end-wall in a hallway and discovers the secret room with a rotting skeleton next to a Christmas tree. But the unseen killer arrives and knocks Marcus out. When he regains consciousness, he finds the house on fire, and Gianna by his side who arrived in the nick of time to pull him out of the house.Marcus and Gianna go to the villa caretaker's house to call the police and fire department when Marcus discovers that the caretaker's young daughter, Olga, had drew an identical drawing of the little boy with a bloody knife standing next to a Christmas tree with the murder victim. Olga tells them that she found the drawing and copied it from old file archives at her junior high school. Marcus and Gianna break into the Da Vinci Junior High School to search the archives for the drawing, when Gianna is stabbed by the killer and Marcus finds the painting, with the name on it which is Carlo, who appears before Marcus holding a gun and threatening to kill him for getting too close. Just then, the police led by the superintendent Calcabrini arrive and Carlo flees, but in a twist of fate, he gets sideswiped by a passing garbage truck which he gets hooked onto the fender and gets dragged down the street to his gruesome death.With the case apparently wrapped up with Carlo being the killer, Marcus drops off the severely wounded Gianna at the hospital, but in going back to the scene of the crime, tries to remember what he thought he saw. Carlo could not have murdered Helga Ulmann because he was with Marcus on the street when they saw the killer stabbing Ulmann. Marcus enters the murder victim's apartment and, after looking around, finally remembers what he saw in a mirror reflection that night: the face of the killer.The identity of the killer is finally revealed to be Carlo's insane mother Martha (Clara Calamai). Martha suddenly appears in the apartment and reveals everything to Marcus; when Carlo was still a child, he watched as his mother murdered his father when he tried to have her committed to a mental hospital. The young Carlo and mother then entombed the body in a room of their house.Wielding a meat cleaver, Martha chases Marcus around the complex and into the foyer with an elevator. Marcus gets hit in the shoulder by the cleaver, and, in the process, he kicks Martha toward the elevator shaft. Her excessively long necklace slips in through the crossed metal bars. She tries to pull herself away and, in doing so, the large pendant on the end of the necklace becomes lodged between two small metal bars. As Martha is desperately trying free her necklace, Marcus Daly realizes she is caught and presses the button to activate the lift. It travels downward and the necklace starts choking her tightly. Her hands are clad in black leather gloves, making her fingers much too thick to slip in-between her neck and the necklace to try and save herself before it's too late. The elevator provides so much force that the necklace ends up cutting through her neck, decapitating her... creating a huge 'deep red' bloodstain all over the marble floor.