To save the Library of the Unwritten in Hell, former librarian Claire and her allies may have to destroy it first, in the final book of the bestselling fantasy trilogy

Claire, rakish Hero, angel Rami, and muse-turned-librarian Brevity have accomplished the impossible by discovering the true nature of unwritten books. But now that the secret is out, in its quest for power Hell will be coming for every wing of the Library. To protect the Unwritten Wing and stave off the insidious reach of Malphas, one of Hell's most bloodthirsty generals, Claire and her friends will have to decide how much they're willing to sacrifice to keep their vulnerable corner of the afterlife.