Downshadow

Watchman by day, vigilante by night, Shadowbane's world is turned upside down when he runs across a powerful wizard—in the form of a confused, hunted girl who finds herself at the heart of a fell plot. When his friends start dying and the girl is kidnapped, Shadowbane must choose between the darkness and the light in his heart: to avenge the deaths of his friends, or to let the villain live to face—and possibly escape—justice.