The naked body of an aristocratic youth turns up in the sewers beneath Bluegate Fields, one of London's most notorious slums. But Arthur Waybourne had been drowned in his bath, not in the Thames. More shocking still is the discovery that the boy had been violated and infected with syphilis before his murder. Despite Inspector Thomas Pitt's efforts to investigate the crime, the family closes ranks, leaving him to wonder what they are hiding.
All evidence points to Arthur's tutor, Jerome, as the murderer, but Pitt and his wife, Charlotte, don't believe the answer is so simple. But if not Jerome, then who? To learn the truth, Charlotte uses her familiarity with the upper classes to draw aside the curtain of lies, while Pitt defies his superior and the boy's family to follow a trail that leads him into the foulest streets of London through a web of deceit. In a race against time, Thomas and Charlotte must find the real killer to save Jerome from the hangman's noose.