On a train trip, Richard Grant, Lionel Barrymore a seasoned lawyer who has spent years prosecuting and defending murder cases, voices a chilling belief: murder can be justified, and a clever man might commit it undetected. He is bound for the isolated estate of his wealthy client and friend Gordon Rich, Alan Mowbray. His daughter, Barbara 'Babs' Grant, Madge Evans, surprises him at the station by revealing she has already been at the estate for a week. The contrast between Grant’s forensic pragmatism and Barbara’s ardent stubbornness threads the mood of the journey ahead, setting up a claustrophobic drama of desire, power, and danger.
At Rich's mansion, Rich asks Grant to rewrite his will, including bequests to all his former mistresses—except a 16-year-old whom Grant believes committed suicide. Rich explains that he intends to marry Barbara; Grant is appalled. He pleads with his daughter, stressing the age difference and Rich's indecent character, but Barbara's love for Rich is unwavering. A young suitor of Barbara's, Tommy Osgood, William Bakewell, has also failed to change her mind. The atmosphere thickens with hidden motives as the next days unfold amid careful social ritual and veiled threats.
That evening, during a dinner party, Rich announces the wedding and declares it will take place in the morning. His longtime girlfriend Marjorie West, Kay Francis is dismayed, yet she plays the shell game of affection and possession, hoping to win him back even as she realizes the danger of his fixation on Barbara. After the party, Rich tries to reassure Marjorie that their past will be history once the new alliance is sealed, a promise that rings hollow in the tense air of the estate. Rich orders two servants to watch Grant's bungalow on the grounds, sealing off a potential escape route for Grant’s conscience or guilt. Grant, ever calculating, uses a cutout mounted on a record player to cast a moving shadow on the curtain, simulating that he is pacing restlessly, a small, theater-like deception that underscores the play between appearance and reality.
Meanwhile, Rich goes to Barbara's room and tries to force himself on her, but she recoils in disgust and he leaves, exposing the uneasy intersection of desire and control that threads the entire plot. Rich writes a letter to the police accusing Grant in case he is found dead. Grant sneaks into Rich's room, takes Rich's gun from his desk, and shoots him during a clap of thunder. He places the gun in Rich's hand, takes the incriminating letter, and returns to his room just in time to be seen by the servants. When the body is discovered, Grant insists that Rich must have committed suicide, a disclaimer that only deepens the undercurrent of suspicion among those who know his true capacity for scheming.
Barbara soon informs him that she has changed her mind about the wedding, rendering the crime unnecessary. The revelation jolts the others, especially Marjorie, who now believes murder more plausible than suicide. She determines how Grant concocted his alibi and then finds the imprint of the incriminating letter on the desk blotter, a telltale sign that could unravel him. Yet Grant returns and wrestles the evidence away from her, warning that if she accuses him, he will contrive a murder case against her, since she stands to gain as Rich's beneficiary and was heard screaming when Rich was killed. If she stays silent, she remains free to enjoy Rich's fortune, an offer that props up the film’s moral paradox: the values of wealth, loyalty, and truth are all negotiable in this deadly triangle of desire.
The police soon arrive, and the chief, Grant's old friend, accepts his conclusion that it was suicide. Marjorie, faced with the precarious choice between truth and wealth, finally decides to remain silent—yet the film’s twist will not be denied. Just as the denouement seems poised to hinge on a courtroom confession, a brutal physical reminder of the perilous entanglements around Barbara intervenes: a rigor mortis contraction of Rich's trigger finger fires the gun, fatally wounding Grant. The act prevents a full confession and preserves the fragile balance of power at the estate. Before he dies, Grant asks Tommy to take good care of Barbara, a quiet testament to his lingering paternal instinct amid the chaos. Seeing no reason to hurt Barbara, Marjorie remains silent, leaving the inheritance and the moral questions to linger in the air like a misfired shot in a stormy night.
