Partners now in marriage and in trade, Lady Julia and Nicholas Brisbane have finally returned from abroad to set up housekeeping in London. But merging their respective collections of gadgets, pets and servants leaves little room for the harried newlyweds themselves, let alone Brisbane's private enquiry business.

Among the more unlikely clients: Julia's very proper brother, Lord Bellmont, who swears Brisbane to secrecy about his case. Not about to be left out of anything concerning her beloved—if eccentric—family, spirited Julia soon picks up the trail of the investigation.

It leads to the exclusive Ghost Club, where the alluring Madame Séraphine holds evening séances…and not a few powerful gentlemen in thrall. From this eerie enclave unfolds a lurid tangle of dark deeds, whose tendrils crush reputations and throttle trust.

Shocked to find their investigation spun into salacious newspaper headlines, bristling at the tension it causes between them, the Brisbanes find they must unite or fall. For Bellmont's sake—“ and more—“ they'll face myriad dangers born of dark secrets, the kind men kill to keep….