 In Mexico, the insecure writer Carlos (Víctor Huggo Martin) and his mate, the photographer Ana (Susana Zabaleta), are in crisis of relationship, and lodge for a period in Carlos  apartment their common friend and ex-lover of Ana, Tomas (Demian Bichir), who was traveling around the world for the last years. On the building in the other side of the street, the unfaithful executive Miguel (Jorge Salinas) and his sterile wife and former model Andrea (Cecilia Suárez) are having a troublesome life, and they lodge the former passion of Miguel, the zoologist Maria (Mónica Dionne). After confusions and misunderstandings, the women move together to Miguel s flat, while the men stay together in Carlos  place, disclosing secrets and beginning a war of sexes, where some of them will be hurt.