In late Victorian London, the murder of prostitute Ada McKinley in a bedroom on decrepit Pentecost Alley would hardly cause a ripple, ordinarily. But under the victim's body, police find a Hellfire Club badge inscribed "Finlay Fitzjames," a name which instantly draws Superintendent Thomas Pitt into the case. Fitzjames Senior—immensely wealthy and dangerously powerful—clearly expects Pitt to arrest anyone other than Finlay for Ada's demise. But Pitt is not a man to be intimidated, and with the help of his quick-witted wife Charlotte, he stubbornly pursues this 16th investigation in Anne Perry's enduring historical series—and it is a case that twists and turns much like London's ancient streets.

"Stands as one of her most intricately constructed plots…. Perry packs a triple wallop into the final pages, one climax following another."—Chicago Sun-Times