Bergman (Erland Josephson), or rather: Bergman’s alter ego, is listening to a music box playing the tune of Papageno’s entrance song from “The Magic Flute” when a female figure (Lena Endre) appears behind him. The two of them agree to call her Marianne Vogler. They describe her as extremely attractive, around 40, actress, happily married with the conductor Markus (Thomas Hanzon), with whom she has a daughter Isabelle, aged nine. Bergman wants them to play and fantasize together, and so the figure called Marianne begins to tell her story, the story of her affair with the director David (Krister Henriksson), a close friend of the couple, who, like Markus, works at the state theatre. Their “amour fou” at first takes the lovers to Paris, but ends up having disastrous consequences for all of those involved.
As is the case with many of Ingmar Bergman’s films, he based his screenplay for TROLÖSA on events that he had experienced. He entrusted Liv Ullmann with the direction of the film; she had acting in many of his films and TROLÖSA was the fourth feature film that she directed. Ullmann tells the story from Marianne’s perspective, partly in the form of conversations between Bergman’s alter ego und Marianne, no doubt a figment of his imagination, and partly acted out in the scenes of the film. In the end the faithless have a price to pay for their infidelities.