When the owners of the falaj (the palm grove's irrigation canal) began to quarrel because of a lack of water, Aqil volunteered to go and seek out Abou Hâroûn, the Master of Water, a scholar who travels the country, ready to help the villagers in times of need. Since his parents died in a river of mud, Aqil is looking for peace. But he has another reason to go and meet the old sage. He has a passion for the stars and has questions about the mysterious dial his father left him. How to use it? When he finally finds Abu Hâroûn, the latter warns him: the study of the stars and the firmament can take a whole life. It's a good thing: Aqil has his whole life ahead of him!