In Paris, Marise Aubert, Greer Garson, is discussing her medical condition with Dr. Leclair, Cecil Humphreys, who explains that there is nothing physically wrong with her and that her pain stems from her internal struggles.
Two weeks earlier, a tense visit unfolds as soldier Jean Renaud, Richard Hart, arrives unexpectedly at Marise's cottage. He reveals that he was imprisoned in a Nazi reprisal camp alongside Marise's husband, Paul Aubert, Robert Mitchum, and that Paul told him everything about her. Jean confesses that he saw Paul shot dead, a claim that unsettles Marise and prompts her to tell him to leave—yet a storm forces her to relent and let him stay.
Marise is taken aback by how much Jean seems to know about her, gleaned from Paul during their time in the camp. Jean has fallen in love with her through those stories, but when he makes romantic advances, Marise rebukes him. Yet loneliness narrows her resistance, and she begins to see in Jean a connection to a life she once imagined with Paul. The two share some quiet, hopeful moments that feel like a fragile reset.
A letter from Paul Aubert, Robert Mitchum, arrives, but Jean intercepts it before Marise can read it. The note reveals that Paul is not dead and that he is about to be released from a hospital to return home. Realizing Paul may still be alive complicates Jean’s position, and though he nearly leaves, he stays by her side. Marise contemplates leaving with Jean and selling Paul’s business, but Paul’s imminent return unsettles their plan. When Paul returns to the cottage, the truth of his presence collides with the truth of Jean’s feelings, spiraling toward a confrontation.
Jean retrieves an old gun he found in Paul's office and heads toward the cottage to face Paul. A charged confrontation ensues, with Marise torn between the life she thought she might have with Jean and the reality of Paul’s return. The struggle culminates in tragedy as Jean is killed in a fall from a cliff, a moment that leaves the future uncertain and heavy with consequence.
Back in the present, the doctor urges Marise to return home. She makes her way back to the cottage, where Paul awaits, and they reconnect in a moment of quiet, shaky happiness that hints at healing yet keeps the past close behind them. The film resolves with a renewed, if fragile, bond between Marise and Paul, framed by the memory of the choices that led to this reunion.
