Turn Coat (Dresden Files Series #11)

Jim Butcher's breakthrough #1 New York Times bestseller starring Chicago’s only professional wizard, Harry Dresden.
 
When it comes to the magical ruling body known as the White Council, Harry is thought of as either a black sheep or a sacrificial lamb. And none hold him in more disdain than Morgan, a veteran Warden with a grudge against anyone who bends the rules. But now, Morgan is in trouble. He's been accused of cold-blooded murder—a crime with only one, final punish…