The arrival of María, the new cleaner, at La Laguna Negra boarding school, after escaping from a psychiatric hospital, will disrupt the peaceful life of Héctor, the charismatic headmaster, who has a seemingly perfect relationship with Elsa, the strict head of studies. A closeness will develop between them that Elsa will try to prevent. María is not the only one fleeing a painful past. Marcos and Paula, after the disappearance of their parents, are taken in by the school under the tutelage of Héctor, who is now their only family.