Adapted from Hugo's eponym novel, the story concerns a Guernseyman named Gilliatt, a social outcast who falls in love with Deruchette, the niece of a local shipowner, Mess Lethierry. When Lethierry's ship is wrecked on the Roches Douvres, a perilous reef, Deruchette promises to marry whomever can salvage the ship's steam engine. Gilliatt eagerly volunteers, and the story follows both his physical trials and tribulations.