Natsu tries to save Erza but discovers that the Council had planned her arrest to assert its authority over Fairy Tail. To prove his strength, Natsu and Happy fly off on an S-Class mission without Makarov's permission and persuade Lucy to accompany them. Gray joins them. The mission: to lift the curse of Galuna Island, which turns its inhabitants into demons under the effect of violet moonlight. The team investigates and finds a cult led by Lyon Vastia (Gray's former comrade), who wants to resurrect the demon Deliora (which their mistress Ur sealed).