Esther (Natalia López) and her poet husband Juan (Carlos Reygadas) manage a ranch in the Mexican countryside where they raise fighting bulls. Although they maintain a loving marriage and family life, they operate under an open relationship agreement where Esther is permitted to have outside sexual affairs as long as she remains completely transparent with Juan. However, when Phil (Phil Burgers), an American horse trainer, arrives at the ranch, Esther begins an affair with him that she keeps hidden from Juan. Struggling with jealousy, paranoia, and the collapse of their rules, Juan attempts to control the situation, leading to the disintegration of their marriage.