When Aladdin is summoned to save the magical Sirens from a ruthless and mysterious enemy, he soon discovers that the Key to Hades has been stolen from the sea nymphs' lair. Now the King of Agrabagh must venture deep into the heart of the Dark Continent in search of the legendary entrance to the Underworld. But when a costly mistake unknowingly bestows upon their flying ship all the knowledge of the Universe, plans radically change.