Juan, but he realizes that his love is not returned with the intensity he desires. Pablo is very close to his transsexual sister Tina, a struggling actress. Tina has recently been abandoned by her lesbian lover, a model, who left her in charge of her ten-year-old daughter Ada. Frustrated in her relationship with men, Tina dedicates her time to Ada, being a loving surrogate mother. The precocious Ada does not miss her cold mother. She is happier living with Tina and spending time with Pablo, on whom she has a crush. Tina, Ada, and Pablo form an unusual family unit. Pablo looks after them both. For his next project, Pablo writes an adaptation of Cocteau's monologue-play The Human Voice, to be performed by his sister. At the play's opening night, Pablo meets Antonio, a young man who has been obsessed with the director since he watched the gay theme film The Paradigms of the Mussel. At the end of the evening, they go home together and have sex. For Antonio this is his first homosexual experience, while Pablo considers it just a lusty episode. Pablo is still in love with his long-time lover, Juan. Antonio misunderstands Pablo's intentions and takes their encounter as a relationship. He soon reveals his possessive character as a lover. Antonio comes across a love letter addressed to Pablo, signed by Juan, but which in fact was written by Pablo to himself. The letter makes Antonio fall into a jealous rage, but he has to return to his native Andalusia, where he lives with his domineering German mother. As he promised, Pablo sends Antonio a letter signed Laura P, the name of a character inspired by his sister in a script he is writing. In his letter, Pablo tells Antonio that he loves Juan and intends to join him. However, Antonio, who is jealous and wants to get rid of Juan, gets there first. Antonio wants to possess everything that belongs to Pablo, and tries to have sex with Juan. When Juan rebukes his advances, Antonio throws him off a cliff. After killing his rival, Antonio quickly heads for his hometown. Pablo becomes a suspect in the crime because the police have found in Juan's fist a piece of clothing that matches a distinctive shirt owned by Pablo. In fact, Antonio was wearing an exact replica when he killed Juan. Pablo drives down to see his