Natsu, Lucy, and Happy embark on the S-Class quest to lift a curse on Galuna Island that turns its residents into demons when they are exposed to moonlight. Gray tracks the three down to return them to the guildhall, but Natsu knocks him unconscious and takes him with them, believing they can avoid punishment if they fulfill the mission. After the ferryman of their boat mysteriously disappears mid-route, the wizards are shipwrecked on the island and witness the local villagers transform into demons firsthand. While exploring, the wizards discover the frozen body of Deliora—a demon whom Gray's magic teacher, Ur, sacrificed herself for to seal away—and a cult of wizards who are attempting to resurrect the demon.