The island of Sein in the nineteenth century, in Brittany. A crude population lives here on these windy shores, estranged from the rest of the world. No priest comes here anymore because they are sinners and wreckers. Therefore, the sacristan will act as a priest. The inhabitants from the island do need religion, even if theirs is close to superstition. And they do believe in their new officiant, even if the latter does not dare to do everything a priest does (the sacraments). But little by little, he would, were it not for the coming of a true religious figure escorted by gendarmes.