In "The Haunted House: The Sky Goblin vs. Jormungandr," Hari and Doori face a new threat when the mythical Sky Goblin, a powerful being capable of controlling storms, appears. This ancient entity is entangled with the monstrous serpent Jormungandr, who seeks to plunge the world into eternal darkness. The duo, with the help of their ghost friends, must find a way to stop both beings before catastrophe strikes.