"The Sin Eaters" ended with lightning.

Eliza Reyes watched her bestial new friend disintegrate in orbit, her promise to be his sin eater fresh on her lips. Leyevi Fen Enkidu discovered a cache of the Hollow Folk's forbidden weapons in the wake of Ulanbatar, swearing to burn the deceivers from their hidden fortresses.

In the thrilling sequel, Eliza Reyes hunts Teutonic terrorists a century after witnessing the lightning's birth.

The Teutoburgkinder see the burning sky as proof of Ragnarok. Eliza sails to the bottom of the world in a desperate attempt to maintain the blockade safeguarding the world from American lightning. What she finds waiting at sea splits the chasm left by Charlie into an abyss.

What good is choice when your reality shatters?

The Forty Dragons will not tolerate Leyevi Fen Enkidu's wrath.

So says the ruling council of the planet's only government. Mei, a bookish student of obscure Asian tribal languages, finds herself forced Above the World for the first time to help investigate what threat Fen's people might pose. But experiencing the enemy has a way of making people question all they thought they knew. Who is the real wild mutants living freely beneath the sky or underground cities crafting weapons from the lightning?

Mei must The protection of the old world or the creation of the new. There is no room for both.

And the stricken world wonders what happened to the man who broke the sky.