The swarm descends

"When Caw successfully defeated the Spinning Man, he was sure that Blackstone would be safe. He was wrong. The villainous ferals have found a new leader, one who has been quietly biding her time since the days of the Dark Summer. And Caw has something she wants--something she needs. With Lydia and his loyal crows by his side, Caw believes he can protect himself and his city. But the Mother of Flies won't stop hunting Caw until she has claimed her victory...and it will take more than crows to defeat her"--Dust jacket.