Child of fire - Harry Connolly

Ray Lilly is living on borrowed time. He’s the driver for Annalise Powliss, a high-ranking member of the Twenty Palace Society, a group of sorcerers devoted to hunting down and executing rogue magicians. But because Ray betrayed her once, Annalise is looking for an excuse to kill him–or let someone else do the job.

Unfortunately for both of them, Annalise’s next mission goes wrong, leaving her critically injured. With the little magic he controls, Ray must complete her assignment alone. Not only does he have to stop a sorcerer who’s sacrificing dozens of innocent lives in exchange for supernatural power, he must find–and destroy–the source of that inhuman magic.