Letty Lynton, Joan Crawford, a New York City socialite who has been living in Montevideo, Uruguay, wants to end her affair with Emile Renaul [Nils Asther], but the only way out is to leave the country. On a steamship bound for the United States, she encounters a wealthy American, Jerry Darrow [Robert Montgomery], and they repeatedly find themselves seated at the same table for meals, sparking a growing, undeniable attraction. Over two weeks at sea, their bond deepens into love, and a shared sense of possibility begins to brighten Letty’s outlook.
On Christmas Eve, the captain distributes telegrams as gifts, and Letty, traveling alone, has none. Jerry pretends to be without one as well, a small gesture that moves them both. Their kiss marks a turning point, and Letty starts to believe she can finally start a new life. When Jerry comes to her cabin to propose, she accepts, imagining a path to happiness she has long denied herself.
Back in New York, Letty is stunned to see Emile waiting on the dock. He has flown from South America to reclaim her and intends to take her back. After arranging to meet him later, Letty leaves Emile with her trunk and hurries home to speak with her mother. Jerry phones to say they have been invited to his parents’ home in Upstate New York and will depart that night, once Letty has told her mother about the engagement.
Mrs. Lynton, Letty’s mother [May Robson], is embittered and distant, offering little warmth or stability to Letty, whom she still views as irresponsible. Emile soon arrives on the pier to press the issue, having learned of the engagement from newspapers. He warns Letty to meet him in his hotel room that night or he will reveal her explicit love letters. Cornered and frightened, Letty resolves to end her life rather than surrender to Emile’s control, clinging to a sliver of hope that she might still regain her freedom.
She phones Jerry to delay their departure to the next day, then goes to Emile’s hotel with a bottle of poison. She pleads for a chance at happiness, but Emile remains possessive, insisting the affair will end only on his terms. When a knock at the door distracts Emile, Letty pours the poison into a champagne glass and contemplates drinking it herself. As Emile returns, he strikes her and drinks from her glass, swallowing the fatal poison himself. In a whirlwind of fear and guilt, Letty watches as he dies, then cries out that she’s glad he’s dying—even if it means she will pay for it later. She cleans the room of fingerprints and leaves, preserving her own escape.
The next day, Letty and Jerry arrive at his parents’ home, where a New York detective arrives to question Letty and take her with him. District Attorney John J. Haney [Lewis Stone] questions the group, accusing Letty of murder and presenting Emile’s letters as evidence. Letty admits she visited Emile, but Jerry interrupts by asserting that they spent the night together at Jerry’s apartment and that he knew about the letters. Mrs. Lynton corroborates Jerry’s story, claiming she followed Letty to Jerry’s apartment and overheard Emile threaten to kill himself if Letty did not return. Miranda, Letty’s maid [Louise Closser Hale], also corroborates the tale. With the testimonies in, Haney declares the case closed and Letty is free to go.
This labyrinth of desire, danger, and double lives unfolds in a world where appearances mask the truth, and where a single fateful decision reshapes the lives of everyone involved.
