Claire Millaud, a middle-aged professor of French literature, shares custody of her two sons with her ex-husband Gilles. She embarks on a fraught affair with the younger Ludovic Dalaux, a relationship he treats as casual from the start. He soon pulls away, and when Claire calls, his roommate Alex Chelly answers the phone and pretends Ludo is out.
Claire then creates a fake online persona, “Clara Antunès,” to connect with Alex Chelly, gradually building an emotional and cybersexual bond. When Alex grows insistent on meeting in person, Claire, still as Clara, claims she’s getting married and moving to Brazil, effectively calling off the affair to avoid a real-life encounter. Alex deletes his profile, and Claire turns to Ludovic to learn more about him. He reveals that Alex, heartbroken after encountering a supposed “psychopath” within Clara’s online world, has killed himself.
These events unfold within a framework of psychotherapy sessions between Claire and Dr. Catherine Bormans. The therapist asks Claire to be forthright about a detail that does not square with the rest of her story, which leads Claire to admit that the photos and videos of “Clara” used in her communications with Alex actually belong to her estranged niece, Katia, whom she helped raise.
Bormans then receives a dossier from Claire, containing a version of the Clara story in which Alex’s acquaintance with Clara grows more concrete, yet ends with a twist that alters the trajectory of their relationship. In this alternate tale, Alex and Claire become live-in lovers, but lingering doubt about whether Clara still has a place in his heart drives Claire to revive the persona and pursue a face-to-face meeting. Alex, attempting to reach Clara, discovers the hidden phone Claire used for Clara; when he confronts Claire, the moment unsettles her to the extent that she steps backward into traffic and is presumably killed. Bormans concludes from the narrative that Claire is unwilling to grant herself happiness, even within fiction, and she is revealed to be a patient in a clinic for a mental disorder.
In a later development, Bormans seeks out Ludovic, who explains that he had sensed Claire’s manipulation after hearing Clara’s voice in one of her calls to Alex and had later fabricated Alex’s supposed death to test her. The psychiatrist then passes this information to Claire, who admits that Gilles left her for the sake of her niece Katia. With this revelation, Claire seems ready to consider leaving the institution.
In the final scene, Claire dials Alex’s number from Clara’s phone, suggesting a fragile thread of possibility that perhaps happiness, even if risky, might still be worth pursuing.
