Alone at home with nothing to do, Antoine’s doubts slowly transform into obsession. He demands proof of identity from his wife who he accuses of being someone else. Elizabeth is patient. She knows that her husband needs help. She tries to get Thierry and the psychiatrist involved.

Antoine and Elizabeth’s life slowly becomes hell. She leaves to live with her friend Rita. Antoine moves to his boat, changes identity, and begins seducing Rita in order to pursue his investigation. He remains determined to unmask the “impostor” who posses as Elizabeth…