The Witch Thief is the sixth book that’s part of the Unbound series. The narrative looks at Joarr Enge and Amma. Joarr Enge, a dragon-shifter, has been biding his time for a century to exact his revenge. Despite his doubt about the powers of the chalice he was entrusted to protect, he refuses to let Amma, the enchanting witch who deceived him, get away.