A murdered opera singer. A duke drenched in her blood. For Bow Street Officer Hugh Marsden, the brutal killing is a straightforward case. Ever since his exile from polite society, the chance to arrest a high and mighty peer of the realm has never presented itself. Hugh won't snub the opportunity now. But Audrey Sinclair, the Duchess of Fournier, is certain her husband is wrongly accused, and she's determined to prove it to the arrogant Bow Street officer, even if she must employ her most peculiar ability—or perhaps curse—to guide her investigation. After all, a duchess can do as she pleases.

Marianne Edgewood is perfectly capable of running Brindale Castle, if only the task would be left to her. A centuries-old house of stone is solid, unchanging, whereas people are not to be relied upon. It matters little that a stranger inherited the castle. She must simply find a way to stay.

Rowley Knight, Duke of Knighton, is too busy being a duke to bother with such nonsense as love. With three heirs, he is in no hurry whatsoever to succumb to the lures of the leg-shackles. He is content managing his siblings and estates, and avoiding society whenever possible. If he can only find someone to manage his young sister, life can go back to its proper order.

She's an unconventional lady who has traveled the world, practices the art of self-defense most excellently, and has an interesting tattoo in—ahem—a very unusual place. He's a former member of the Metropolitan Police, now a private investigator, who grew up on the poverty-ridden streets of Edinburgh and has worked the dangerous back alleys of London's notorious East End. A vicious murder brings them together in a race against time that takes them from the sordid back streets of London into the elite private clubs of the powerful and rich.

Lady Ludmilla Windmere is mortified. The spinster extraordinaire has fallen in love with her best friend, and that cannot be. The problem? She hasn't met him. Not once. For they have only ever corresponded by letter. When she sets out to uncover his identity, her world shatters. For Addy turns out to be none other but London's worst rake. Adrian St. Addington is perturbed. The rakehell extraordinaire is developing a marked tendre for a spinster, and that cannot be. The problem? She might be mistaking him for someone he is not. Or, what is worse, know precisely who he is.