The Enchanter Heir (2013) is the fourth novel in the Heir Chronicles young adult contemporary fantasy series by Cinda Williams Chima which also includes The Warrior Heir (2006), The Wizard Heir (2007), and The Dragon Heir (2008), and one more book forthcoming.
Tonino is the only person in the famous Montana household who wasn't born with an instinct for creating spells, but he has other gifts. His ability to communicate with cats just might help defend the city of Caprona against a mysterious enchanter -- but only if Tonino can learn to cooperate with a girl from the hated Petrocchi family of spell-makers.
The quest was over. The Orb of Aldur was restored. And once again, with the crowning of Garion, there was a descendant of Riva Iron-grip to rule as Overlord of the West. But the Prophecy was unfulfilled. In the east, the evil God Torak was about to awaken and seek dominion. Somehow, Garion had to face the God, to kill or be killed. On the outcome of that dread duel rested the destiny of the world. Now, accompanied by his grandfather, the ancient sorcerer Belgarath, Garion headed toward the City of Endless Night, where Torak awaited him.