SYNOPSIS

The film begins on a foggy night in London after the murder of famous opera singer, Alice Alquist. Her young niece, Paula, having discovered the body, is placed in the hands of a guardian.

Twenty years later, Paula has grown up and married pianist Gregory Anton. The couple moves to Paula's ancestral home. Upon seeing the room in which her aunt was murdered, Paula becomes upset. To calm her, Gregory suggests they seal off all the old things on the third floor and replace them with their own furnishings so she doesn't have to live among haunting memories.

Strange things begin to happen soon after the move. The affectionate and doting Gregory loses his temper easily and becomes possessive. He convinces Paula that she is becoming forgetful and confronts her about stealing items--including his personal belongings--and hiding them. He warns her that her memory lapses are becoming unnerving, and reveals that Paula's mother, before her death, was committed to an insane asylum. This alarms Paula because she has been hearing footsteps in the attic and has noticed the gaslights dimming every night. Paula's vitality and happiness dissolve to paranoia and fear.

A gossipy neighbor, interested in the strange couple, discusses the Antons with a Scotland Yard detective, Brian Cameron. Suspicious of Gregory's intentions, the detective makes inquiries into the death of Paula's aunt and deduces that Gregory married Paula to find her aunt's jewels that were never recovered after her death. When Gregory leaves the house one night, Cameron rushes to warn Paula about his discoveries. On the verge of a nervous breakdown, Paula doesn't want to believe her husband is responsible for her deterioration. To prove his case, Cameron rummages through Gregory's desk and finds many "missing" items and a letter Gregory wrote 20 years earlier to Paula's aunt. Cameron also notices the gaslights dimming, and Paula, relieved and dismayed at the same time, accepts her husband's deceitfulness.

When Gregory returns, he notices Paula has been through his things and resolves to kill her as he did her aunt. Cameron stops the murder attempt and ties up Gregory in the attic until the police arrive. Cameron leads Paula out of the room, and the scene closes with Cameron offering his support and friendship to a grateful Paula.