The Mime Order (Bone Season #2) by Samantha Shannon
Paige Mahoney has escaped the brutal prison camp of Sheol I, but her problems have only just begun: many of the survivors are missing and she is the most wanted person in London . . .
As Scion turns its all-seeing eye on Paige, the mime-lords and mime-queens of the city's gangs are invited to a rare meeting of the Unnatural Assembly. Jaxon Hall and his Seven Seals prepare to take center stage, but there are bitter fault lines running through the clairvoyant community and dark secrets around every corner.
Then the Rephaim begin crawling out from the shadows. Paige must keep moving, from Seven Dials to Grub Street to the secret catacombs of Camden, until the fate of the underworld can be decided.