In the year 1605, a young widow, pregnant and alone, seeks sanctuary at the small Abbey of Sainte Marie-de-la-mer on the island of Noirs Moustiers off the Brittany coast. After the birth of her daughter, she takes up the veil, and a new name, Soeur Auguste. But the peace she has found in re-mote isolation is shattered five years later by the events that follow the death of her kind benefactress, the Reverend Mother. When a new abbess -- the daughter of a corrupt noble family elevated by the murder of King Henri IV -- arrives at Sainte Marie-de-la-mer, she does not arrive alone. With her is her personal confessor and spiritual guide, Pßere Colombin, a man Soeur Auguste knows all too well. For the newcomer is Guy LeMerle, a charlatan and seducer now masquerading as a priest, and the one man she fears more than any other.