Calisto, a handsome young nobleman, enters the orchard where he finds Melibea, with whom he falls deeply in love. Faced with her rejection and advised by his servant Sempronio, he decides to entrust his care to Celestina, to achieve through her the love of Melibea. The procuress manages through trickery that Melibea falls in love with Calisto. The latter's servants try to exploit their master's passion for their own benefit: he had promised Celestina a gold chain if she helped him to surrender Melibea's will. When this happens, the servants demand their share and, when Celestina refuses, they kill her. They are arrested and executed by justice.
In the last meeting of Calisto and Melibea, the young mancebo jumping the wall of the garden of Melibea to help his servant Sosia falls and dies. This leads to Melibea's suicide before the compassionate gaze of her father Pleberio, who ends the tragicomedy with moral and existentialist reflections.