In 1852, the famine on a desolate Britanny's island named Blaz-Mor, off the coast of Finistère. Some residents exalted hold responsible the young Moira, equivalent to a witch. The old Marnez, "head" of the island, is trying to restore calm and opposes Yann Le Heart, the fiancé of his daughter Louise Kermelen, who wants causing a shipwreck to save the island from famine.