In the village of Fuentecilla is a medicinal spa which was very popular in the past but has now been forgotten by the public. To bring back the tourists, the "prominent men" of the village organize a fake miracle: the apparition of San Dimas, the local patron saint, which will take place every Thursday night. At first it works, but trouble begins when a stranger appears, claiming that he knows what's going on and making peculiar demands in exchange for his silence.