A mysterious and unpleasant-looking man shows up one day at Canica’s house with a face of few friends. He claims to be from the electric company and asks for the key to the town house, because he needs to get in. Apparently there is an overload of energy, but something doesn’t add up for Canica: how can there be excessive electricity consumption in the village house if it has been uninhabited for years?

Moved by restlessness and curiosity, the boy decides to investigate, and gets on a train bound for Castañuela de Arriba without knowing the number of surprises he will find and the dangers he will have to face.