Cartagena, 1625: Don Santiago Alvarez de Armias meets with some acquaintances for drinks near the Plaza de los Coches. One of them shares a tale of his latest conquest, which resulted in a broken bed, bragging that the woman's husband remains oblivious.

Don Santiago thinks nothing of the boastful tale until he returns home, where his wife informs him that their bed is damaged. Overcome by rage, he kills her, with the pieces of the bed where she betrayed him. The Alcalde is summoned and his murder is found to be justified, for the servants all attest to his wife's infidelity.

But his ordeal has only begun. For with her dying breath his wife has cursed him for all time, and the next morning Don Santiago awakens to discover the horns of the cuckold upon his head.