The doorway to the Otherworld has been closed but at a terrible cost. Theo has been trapped on the other side while the Demon Nathaniel searches for one of the lost crossroads of the Underworld. With the help of the God Hades, who she doesn’t trust, Olivia crosses over and with nothing but a flashlight, a broken Demon collar, a Grimoire and a compass that doesn’t work she must risk everything to find him. As she searches she keeps catching glimpses of the real world. It’s only then Olivia realises when they closed the doorway something dark and ancient was left behind, trapped in Mercy. She watches helplessly from other side as the residents of Mercy begin falling into mysterious comas and it becomes clear that whatever is stalking the streets of her town is stealing human souls.
Olivia is torn, faced with an impossible situation and the clock is ticking. Even if she manages to find Theo she knows she must make a choice, stop the soul collector or go after Nathaniel, knowing that if he reaches the crossroad before her, she will have to make a deal with the Keeper of the crossroad and the price may be her own soul.