Forced from London after the death of Brunel, Thorn and her people - the Stokers - reside in the Graveyard; a wasted landscape of scrap metal and disused railway carriages. Shunned by her own people for her family's part in their exile, Thorn's skill with animals is the only thing saving her from banishment. With her friend Lurgo, she hunts the great tri-horned monsters in the surrounding swamps, desperately trying to keep control of her strange power and restore her family's soiled name.
Now Brunel's old Wall is moving again, expanding over the English countryside. And with it comes a horror that should have been long dead - once human creatures turned maniacal by a diet of lead and soot. The Stokers propose a suicide mission, a last-ditch effort to reclaim their home - sending Thorn into the Wall to die; an expendable distraction to ensure their own survival.
But Thorn has other ideas. Together with Lurgo, a blind adventurer, an eccentric menagerie proprietor and a tame triceratops, she sets out to stop the new threat. In a world dominated by powerful men and fierce mechanical monsters, can one woman triumph where so many have failed?
