The Demon Must Die. Even being vanquished to Hell didn't stop Kostucha, the demon of hungry souls. Everly knows what she must do in order to save all the trapped ghosts. With only one person to turn to, Everly must confront her feelings for Jet in order to go to Hell where she might be stuck for all eternity. In the third soul-crushing book of the trilogy, there is nothing Everly won't do in order to save everyone she loves.