Superintendent Thomas Pitt's rise to commander of the Bow Street station has carried him above the sordid run of London crime, but when Whitechapel prostitute Ada McKinley is tortured and strangled two years after the reign of Jack the Ripper, a cuffiink and a button from the defunct Hellfire Club on the scene make the case sensitive enough to bring in Pitt. Both articles are traced to Finlay FitzJames, a young diplomat whose wealthy, ruthless father Augustus's massive contempt for Pitt and his mission casts his son in an even more suspicious light. Pitt, keenly aware of the pressure to arrest someone else, is relieved when his own wife Charlotte and her sister Emily Radley, insinuating themselves into the confidence of Finlay's sister Tallulah, uncover an alibi Finlay cannot make public--and even more relieved when he extracts a confession from a pimp that seems to close the case. A trial follows, as well as a speedy execution--and then, to Pitt's horror, there's a second murder exactly like the first, linked to Finlay by still another scrap of haberdashery. If Finlay is innocent, who is so determined to incriminate him? And if he's guilty, how can Pitt bring him to book when he's being ridiculed all over town for hanging the wrong man? Repetitious and yet perfunctory in probing the suspects; and bits of the truth, at least, are obvious from the beginning. Still, the mystification, and the intensity of Pitt's dilemma, are genuine. Altogether, Perry's best book since Defend and Betray (1992).