In
1875, after world-famous
opera singer Alice Alquist is murdered at her home in
Victorian London, her
orphan niece Paula is sent to
Italy, eventually studying opera to follow in Alice's footsteps. During her voice lessons, Paula is charmed by and marries her accompanist, Gregory Anton, after a two-week whirlwind romance. They settle in London, where Paula has inherited her late aunt's long-vacant townhouse. Paula grapples with the memory of her aunt's murder, and Gregory suggests storing Alice's furnishings in the attic. When Paula finds a letter to her aunt from a man named Sergis Bauer, Gregory reacts violently but apologizes. He hires a young maid, Nancy, insisting that she take instructions from him instead of his "high-strung" wife. Paula is perplexed when Gregory begins to chide her supposed forgetfulness. On a visit to the
Tower of London, she cannot find an heirloom
brooch he gave her, although he stored it safely in her handbag. Gregory then begins to berate her for denying that she removed paintings from the wall, hiding them in odd corners of the house. Disturbed by noises coming from the boarded-up attic when Gregory is not home, Paula notices the
gaslights also dim for no apparent reason. Gregory brazenly flirts with Nancy, whose open disrespect worsens Paula’s nerves. Paula's anxious behavior is noticed by
Inspector Brian Cameron of
Scotland Yard, a childhood admirer of Alice. Struck by Paula's resemblance to her aunt, Cameron attempts to reopen the
cold case, discovering that Alice owned precious royal jewels that were not recovered after Alice's murder. Isolating his wife from the world, Gregory convinces her that she is unstable and a
kleptomaniac, too unwell to be in public. When Paula insists on attending a recital hosted by an old family friend, Gregory accuses Paula of stealing his
pocket watch during the event. When he "finds" it in her handbag, Paula becomes hysterical in front of the guests, who include Cameron. Taking Paula home, Gregory angrily claims that her mother died in an
asylum, and that the letter she discovered from Sergis Bauer never existed. Doubting her own sanity, Paula breaks down. Meanwhile, Cameron has recruited a patrolman to watch Gregory, who often visits an abandoned adjoining house; flirting with Nancy, the policeman learns that Gregory is planning to institutionalize Paula. While Gregory is out, Cameron offers Paula his help, confirming that the attic noises and flickering gaslights are real. He deduces that Gregory has been entering his own attic through a skylight via the adjoining vacant house to search furtively through Alice's belongings for her hidden jewels. When Gregory lights the attic lights, the gas is reduced to the downstairs lights. Cameron pries open Gregory's desk, and Paula finds the letter from Bauer that her husband insisted was a delusion. Cameron expresses that Gregory is systematically driving her into madness. "Gregory" is actually Sergis Bauer, who murdered Alice but was interrupted by a young Paula before he could find her jewels. His marriage to Paula was a scheme to gain access to her aunt's home, followed by a strategy to have Paula institutionalized, gaining full access to Alice's estate. Simultaneously, Sergis discovers Alice's jewels hidden in plain sight, sewn into one of Alice's famous costumes. Returning downstairs, he finds his desk unlocked. He questions the mentally exhausted Paula, who admits the desk was opened by a man that was visiting her. To protect Paula, the kindly
cook, Elizabeth, denies seeing any man and assures Sergis that this was merely a figment of Paula's imagination, driving Paula to despair. Cameron appears and confronts Sergis, chasing him into the attic and tying him to a chair. Finally convinced of her own sanity, Paula consents to Sergis’s request to be left alone with him, where Sergis urges Paula to cut him free. Paula taunts him, searching his desk for an imaginary knife to cut him free, and instead finding the "missing" brooch. As the police drive Sergis away, Cameron expresses interest in seeing Paula again. ==Cast==