Three builders working on the renovation of an old house find a mysterious object hidden behind a wall and decide to bring it out of its hiding place. When the squad leader, Julián, touches it, he feels a cold, intense and unpleasant shock. After that he no longer wants to touch it and would like to get rid of it by warning the owner of the house. However Hugo, another of the workers, believes the object might be valuable and has decided to keep it.