A seemingly mystical murder takes Captain Sophie Maliquot back to the Mont-Saint-Michel region where she spent part of her childhood and where her father, who died years earlier, is buried. There she meets Father Florentin, a charismatic priest who carries out exorcisms. The very rational Sophie is annoyed by the silence of this priest, who, in the name of values she doesn't share, refuses to inform on his followers. She finds him puzzling, but she's far from suspecting that a weighty secret unites them.
—Happy_Evil_Dude