The Gate Thief by Orson Scott Card -- 380 pages
Here on Earth, Danny North is still in high school, yet he holds in his heart and mind all the stolen outselves of thirteen centuries of gatemages. The Families still want to kill him if they can't control him…and they can't control him. He is far too powerful.
And on Westil, Wad is now nearly powerless—he lost everything to Danny in their struggle. Even if he can survive the revenge of his enemies, he still must somehow make peace with the Gatemage Daniel North.
For when Danny took that power from Loki, he also took the responsibility for the Great Gates. And when he comes face-to-face with the mages who call themselves Bel and Ishtoreth, he will come to understand just why Loki closed the gates all those centuries ago.
This is book #2 of the Mither Mages series. This one just didn't work for me. I'm hoping the third and final book in the series picks things back up.