Egypt, 15th century BC: young Merit and her little brother Ouati risk everything to free the daughter of a cursed god, imprisoned in a secret chamber deep within the temple of Amun. Their journey down the Nile – filled with surprising encounters and stops in unusual places – takes them all the way to the royal palace of Avaris, in the North of the country, guided by a single clue: a mysterious hieroglyph of a bull.