At the beginning of the 1820s, in the Channel Islands, the shipowner Mess Lethierry revolutionized the island of Guernsey by connecting it to Saint-Malo thanks to the first steamboat, a steamer that he named La Durande. But one day La Durande runs aground between the formidable Dover reefs and its pilot, Clubin, mysteriously disappears. Mess Lethierry then promises to give the hand of Déruchette, his niece and orphan goddaughter whom he raised, to the one who brings him back his Durande. Gilliatt, worker of the sea and force of nature, kept away by the inhabitants, because suspected of having some connections with spirits (and nicknamed, therefore, Gilliatt the Evil One), lifelong lover of Déruchette, volunteers. He will face the raging elements and mysterious things of the sea and bring back La Durande. But when he discovers that Déruchette is in love with the young Reverend Ebenezer, he fades away and, in despair, abandons himself forever in the arms of his other lover: the sea.