In the village of Fuentecilla, there is a medicinal spa which was very popular in the past but that now has been forgotten by the public. In order 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.