Diana (Amparo Muñoz) is a young woman trapped in an unfulfilling marriage with Marcos (Simón Andreu), a wealthy and prominent man who suffers from impotence and cannot satisfy her physically or emotionally. Yearning for passion and freedom, Diana begins a chance, intense affair with Juan (Patxi Andión), a handsome gas station worker. As their hidden sexual connection deepens into a volatile obsession, Marcos becomes aware of his wife's secret life and devises a calculated, sinister plan to exploit the relationship for his own ends, plunging all three into a dangerous game of manipulation, jealousy, and betrayal.