L E Modesitt Jr

Kharl is the best cooper in Brysta, and his life has been as snug and regular as his barrels. But in the course of just a few days, it's all staved in. When a young blackstaffer from Recluce is mysteriously murdered in his cooperage, Kharl is summarily jailed. Then, in a shocking turnaround at the trial, his innocent consort is blamed for the killing and quickly executed. Kharl ends up destitute and on the run, but he does take the slain woman's black staff and the book The Basis of Order , which explains the principles of its power. Kharl discovers that he can use the black staff to combat chaos magic and that he needs to because a white wizard is stalking and murdering young women—and seeking Kharl.