When the pieces of a singular figure are unearthed and then joined together, a devil of the lowest category breaks into a small Mediterranean village. From that moment on, the demon will enter the life of a painter named Bernardino, in the affairs of a "modern" marriage, in the existence of a frightened gardener and, finally, in the day-to-day life of the Great Momo.

Segundo López, a mature and very humble man who has arrived in Madrid from Cáceres, his homeland, meets Francisca, with whom he falls in love, and El Chirri, a roguish street urchin with whom he will have adventures all over the huge and hostile city.