Once upon a time, there were two children who had the same nanny: Azur, blond and blue-eyed, son of the lord of the castle, and Asmar, dark-skinned and black-eyed, the nurse's child. Brought up like brothers, the children are suddenly torn apart. But Azur, haunted by the legend of the Djinn the nanny used to tell him, intends to find it in lands beyond the seas. When they grow up, the two foster brothers each go separate ways in search of the fairy. Daring rivals, they find magic lands in a medieval Maghreb, full of dangers and enchantments.