Book Title: Changes
Dresden Files # 12

With the White Council of Wizards and the Red Court in a state of detente, Harry finds himself alone except for a handful of allies - resources utterly inadequate to challenging the Red King and his entire vampire Court. With the life of his child at stake, Susan's humanity hanging in precarious balance and with his own death looming, Dresden must find a new source of strength. In the past, there had always been a line Harry wouldn’t cross, and though dark powers have tempted him time and again, he never gave in. But then, only his own life was at stake.