The measure of the magic - Terry Brooks

Five centuries ago, a catastrophic demon war left the world in ruins. Since then, the survivors - humans, elves and other mutants - have found sanctuary in a mountain valley protected by magic. But now these protective wards have failed, and a ruthless troll army is on the brink of invasion.

Sider Ament was the survivors' only hope for salvation. He was bearer of the last remaining black staff - a powerful talisman passed down through the centuries by the Knights of the Word - and the key to keeping the magic of the world in balance. But now Sider is dead.

To stave off annihilation, the staff's magic must be preserved. Panterra Qu, a young Tracker gifted with the staff at Sider's death, struggles to control its power. And great sacrifices must be made - for all will pay a price if the war between the Word and the Void tips towards darkness.