Ghost in the Tower - Ghost Night, #4

Caina has hated the Imperial Magisterium, the Empire's college of magi, for all her life.and the magi hate and fear her right back. But the Magisterium has much bigger problems right now, and the First Magus is willing to make a deal. If Caina can find the root cause of a mysterious string of suicides, the Magisterium will leave her in peace. Except the suicides are actually murders. And unless Caina is clever, she'll be the murderer's next victim.