Somerville, Massachusetts :, Candlewick Press,, 2015.
332 pages : illustrations, map ; 21 cm.
As winter freezes London, a poisoner strikes without a trace, leaving victims mad with terror, and then dead. Wild Boy and Clarissa must catch the killer. Their hunt will lead them from the city's vilest slums to its grandest palaces, and to a darkness at the heart of its very highest society as they race to save their city and clear their names.