London 1865: Lyle receives a nasty surprise late at night. A young girl on his doorstep, passed out, dying - apparently poisoned - and she's not the first. Something very, very bad is happening to the children in the East End.

Which means there's a mystery to be solved, sending Lyle, Thomas, Tate, and - naturally - Tess out into the wilds of east London. What they find is terrifying: Tess's old crowd of artful dodgers and ace pickpockets are now wandering the streets like zombies, drooling in the workhouses or plain mad in the asylums. And the only clue is a name, half-whispered in fear:

Old Greybags.

The thrilling fourth instalment of the ongoing and unbelievable adventures of Horatio Lyle!