The murder of a prostitute named Ada McKinley in a bedroom on decrepit Pentecost Alley should occasion no stir in Victorias great metropolis, but under the victims body, the police find a Hellfire Club badge inscribed with the name Finlay Fitzjamesa name that instantly draws Superintendent Thomas Pitt into the case. Finlays fatherimmensely wealthy, powerful, and dangerousrefuses to consider the possibility that his son has been in Ada McKinleys bed. The implication is clear: Pitt is to arrest someone other than Finlay Fitzjames for Adas demise. But Thomas Pitt is not a man to be intimidated, and with the help of his quick-witted wife, Charlotte, he stubbornly pursues his investigationone that twists and turns like Londons own ancient streets.