Fifteen-year-old Raim lives in a world where you tie a knot for every promise that you make. Break that promise and you are scarred for life, and cast out into the desert. Raim has worn a simple knot around his wrist for as long as he can remember. No one knows where it came from, and which promise of his it symbolises, but he barely thinks about it at all - not since becoming the most promising young fighter ever to train for the elite Yun guard. But on the most important day of his life, when he binds his life to his best friend (and future king) Khareh, the string bursts into flames and...

From the author of T he Potion Diaries books comes a brand-new series set in a near-future society where technology has the power to open up a whole world of magical possibility