LUNGDON - THE IREMONGER TRILOGY 3

Foulsham is destroyed, Heap House is in ruins and the Iremongers are fugitives. A Smog has descended on London, its nexus a small house in a nondescript street where people are hiding: odd people, dirty people who never come out of doors.
Clod's powers are growing, and Umbitt is moulding him into a weapon to exact his revenge on Parliament and the Royal Family. Regular people are turning into objects in the streets. But Lucy's on her way to Clod through the sewers and underground rivers of London. She has to find him, to stop his anguish, and to save the Queen and London.