Driven insane by the very people he trusted, Bellamy is caught between worlds in a way like never before. He's in the hands of Addariel, the angel both at fault for his fall from grace and the current King of Hell. His mind is only clear when he is inside his own head, and his world is spinning out of control. A terrible experiment that went wrong has left him on the verge of death, and it is up to the Codex of Hell and Addariel to save him.

Then, the strangest things start happening among the demons. They devote themselves to his salvation, claiming him as their mate and, more than that, dedicating the hearts they didn't know they had to him. In his madness, he captures their very souls and changes the nature of the beasts around him. Even Addariel, once only interested in power, shifts his focus.

Elysium, though, is not letting go of him easily. In a misguided attempt to help him, they make a move that could destroy the fragile peace between Zion and Elysium.