A few days before dying in an accident, Guillermo confesses to his friend Eusebio that he has sadomasochistic sexual relations with a mysterious woman. After time, and by chance, Eusebio decides to look for that woman to tell her that Guillermo has died and that therefore he will never call her again. When he finds her he is enchanted by her. He doesn't dare tell her anything that he knows about her, so as not to scare her away. Little by little they fall in love. Eusebio expects her to hit him, humiliate him and sexually abuse him like she did with Guillermo, but Julia only gives him caresses and tenderness. That is the beginning of the terrible doubt that makes its way into Eusebio's thoughts: are they both the same woman? Are the one who whipped Guillermo and the one who calmly hugs him the same person? This is the story of an obsession and a path to hell.