 This is the story of Lucía, a restless kid who suffers a domestic accident and loses a tooth.Santiago, her father, an unemployed chef and Pilar, her mother, a successful architect with work to spare, ease her with the illusion that Ratón Pérez will stop by her room that night, take her tooth and replace it with some money.What they don't know is that the alert sign is already being spread...

A little mouse spying the situation warns another mouse who then warns another who warns another who finally warns... Ratón Pérez!