Kel is an orphan raised to be the 'Sword Catcher,' a body double trained to protect and die in the place of Prince Conor Aurelian in the city-state of Castellane. Lin Caster is a physician from the marginalized Ashkar community who possesses rare and forbidden magical abilities. Their lives intersect as they navigate a dangerous web of political intrigue, criminal underworlds, and a mysterious power that threatens the stability of the kingdom.