Description
Peggy (Judy Geeson), an unassuming twenty-two year old caregiver, has recently married Robert Heller (Ralph Bates), and is scheduled to move with him to a secluded boys' boarding school south of London for his work. The night before she is to meet Robert to leave the city, she is attacked in her home by a one-armed man with a prosthetic hand and falls unconscious. Rattled by the attack, she leaves with Robert the following morning to the boarding school, which is run by headmaster Michael Carmichael (Peter Cushing).
Robert and Peggy arrive at the school, and settle into their chalet across the road from the main school building. They make plans to meet the Carmichaels for dinner that evening. The next day Robert leaves for work. Peggy explores the empty school; she hears the voices of boys chatting, but finds the classrooms to be mysteriously empty. She encounters the headmaster Michael, who shows her around the building; she leaves him in the school and returns to her cottage. Shortly after entering her house she is again attacked. Robert returns and is very concerned about Peggy's mental state; although Peggy insists that she was attacked, he doesn't believe her. He cancels the dinner appointment with the Carmichaels.
Later, Peggy and Robert go for a drive around the sprawling property, where they meet the headmaster's wife, Molly (Joan Collins), who is rabbit hunting. Peggy finds Molly standoffish toward her. That evening, Robert leaves for a meeting in London, and Peggy believes an intruder has come into the chalet; she arms herself with a shotgun. She descends the staircase, and sees Michael entering the front door, and notices that he has a prosthetic arm; panicked, she shoots him, and flees the chalet, but he continues to pursue her. She runs into the school, where she hears a chorus of racket and boys' voices echoing through the halls. Michael corners her in an upstairs dormitory, and she shoots at him again, but he is unresponsive to the gunfire. He approaches her, and she faints.
The following day, Robert returns, finding Peggy in a nearly catatonic state inside the school, and a pool of blood in the hallway. Michael is nowhere to be found. He questions her about what happened, but she says she cannot remember. Robert explains to Peggy that he had originally met Michael when he was working in a hospital as a medical student; the boarding school had nearly burned to the ground in an accident years prior, and, devastated, Michael returned to the property, setting up recordings of boys' laughter and classroom lectures over the building's intercoms to recreate the feeling of the school's former glory days.
That night, Robert meets with Molly in the school; it is revealed that the two are having an affair, and that Robert married the mentally-fragile Peggy in order to coax her into murdering Michael out of fear for her life. Peggy stumbles in on their meeting, and Robert demands she reveal where Michael's body is. Molly goes to search for him, and shortly after, the sound of bells echoes throughout the school. Robert binds Peggy's arms and brings her into the main hall of the school, where Michael's voice comes over the intercom. He reveals that he was aware of Robert and Molly's plot to have him killed, and that he had loaded the shotgun in the chalet with blanks. Robert loads the shotgun with bullets, and shoots at what he believes to be Michael hiding under a sheet covering a couch. When he lifts the sheet, however, he reveals Molly's dead body, bound and gagged.
Robert storms out of the school with Peggy, and attempts to hang her from the tree outside in a staged suicide, but is suddenly grabbed in a strangle grip by Michael. The next morning, two policemen arrive, saying they received a call from Michael. Peggy tells them he's inside the school, and that a new term is beginning. One of the police officers tells her that the school has been shut down for years, until suddenly the sound of a boys' choir begins emanating from the building. In the tree behind the school, Robert's dead body hangs from the noose.
