In this historical mystery from the national bestselling author of Who Slays the Wicked, the abduction and murder of a young boy takes Sebastian St. Cyr from the gritty streets of London to the glittering pleasure haunts of the aristocracy...

London, 1813. One of the city's many homeless children, Benji Thatcher was abducted and murdered--and his younger sister is still missing. Few in authority care about a street urchin's fate, but Sebastian St. Cyr, Viscount Devlin, refuses to let this killer go unpunished.

Uncovering a disturbing pattern of missing children, Sebastian is drawn into a shadowy, sadistic world. As he follows a grim trail that leads from the writings of the debauched Marquis de Sade to the city's most notorious brothels, he comes to a horrifying realization: Someone from society's upper echelon is preying upon the city's most vulnerable. And though dark, powerful forces are moving against him, Sebastian will risk his reputation and his life to keep more innocents from harm...