Ana and Otto are brought together as children when Ana's mother Olga and Otto's father Alvaro meet and fall in love. The two form a strong friendship, and Otto moves in with his father's new family, even though he's promised his divorced mother that he'll never abandon her. As the two mature, their relationship becomes sexual, their first encounter taking place over a geography book open to the arctic circle. But when Otto's mother dies, he's devastated, thinking that it is his fault for having abandoned her in favor of Ana. The story is narrated in a non-linear manner, with events occurring twice, from each character's point of view.