Price of the Gift — Meyari McFarland

Anan shut their eyes, heart hammering in their chest as if it was trying to knock the box out of their arms. They couldn't afford another punishment, not after the last one. But the box held a demon and the master of the library didn't care about Anan. They were just a slave. To destroy the demon, the masters would kill Anan. Unless Anan won a bargain from the demon to free them both.