Four months ago, Mater Viae, the Goddess of London, returned from London-Under- Glass to reclaim her throne. And ever since then, London has been dying.

Streets are wracked by convulsions as muscles of wire and pipe go into spasm, bunching the city into a crippled new geography; pavements flare to thousand-degree fevers, incinerating anyone and anything touching them. Towers crash to the ground, their foundations decayed.

As the streets sicken, so does Beth, drawn ever deeper into the heart of the city, while Pen fights desperately for a way to save her. But when they discover that Mater Viae’s plans for dominion stretch far beyond London’s borders, they must make a choice: Beth has it within her to unleash the city’s oldest and greatest powers – powers that could challenge the vengeful goddess, or destroy the city itself.