A modern allegory to the story of Nineveh, "Helm's Curse" follows Duncan Riddell, who just moved to Green Shoals, an Scottish coastal town that its citizens claim to be under a curse that brings endless rain to the town. Duncan sets out to solve the mystery of this curse and bring it to an end. Along the way, he meets a girl named Rowan who suffers from depression from the haunting memories of her mother and brother's deaths. Duncan helps Rowan to discover God's love and forgiveness while bringing hope to all of Green Shoals.