London, December, 1815. Lady Petra Forsyth has volunteered to assist the Lady Patronesses of Almack’s Assembly Rooms with a series of bachelor-auction dances in the fortnight leading up to Christmas Eve. Over five nights, the families of unmarried ladies will each bid for their daughter to be the evening’s hostess and dance with the five eligible bachelors --- called the Merry Gentlemen in a nod to the season. However, after only the first evening, Petra discovers the dead body of one of the bachelors. The death is declared an accident, but when another bachelor’s life is nearly ended a few days later, Petra fears something more sinister may be afoot. As tensions rise, the Patronesses ask Petra to investigate from within…by pretending to be one of the ladies vying for the bachelors’ attentions.

Lady Petra Forsyth and some of the most illustrious members of the ton descend upon Windsor Castle for a week of royal celebrations, with the highlight being Queen Charlotte’s inaugural patisserie contest for the best bakers employed by England’s finest houses. Not only is Lady Petra’s own cook one of the contestants, but Her Majesty has requested that Petra herself serve as one of the judges. Yet upon arrival, Petra encounters a frantic housemaid pointing to the body of one of Her Majesty’s guests --- and to the valet still tugging at the silk ribbon used to strangle the victim. What’s more, the valet turns out to be Oliver Beecham, the ne’er-do-well brother of Petra’s own lady’s maid, Annie. But when some poisoned tea meant for Petra is consumed by one of her fellow judges, it’s clear that the real killer is still walking the castle’s halls.

London may be cheering the news of Napoleon’s surrender at Waterloo, but Lady Petra Forsyth has little to celebrate after discovering that the death of her viscount fiancé three years earlier was murder. The man responsible is her secret paramour, Duncan Shawcross, yet the scoundrel has disappeared, leaving only a confusing riddle about long-forgotten memories in his wake. Meanwhile, Queen Charlotte has tasked Petra with attending an event at the Asylum for Female Orphans and making inquiries surrounding the death of the orphanage’s matron. There may be a link between the matron’s death and a group of radicals with ties to the aristocracy. Then Petra overhears a nefarious conversation with two other men about a plot to topple the monarchy, set to take place during three days of celebrations currently gripping London.

After losing her beloved fiancé in an accident three years earlier, Lady Petra Forsyth announces in front of London’s loosest lips that she will never marry. A woman of independent means, Petra sees no reason to cede her wealth and freedom to any man now that the love of her life is gone. Instead, she plans to continue enjoying the best of society without any expectations. But when ballroom gossip suggests that a longtime friend has died of a fit due to her “melancholia” while in the care of a questionable physician, Petra vows to use her status to dig deeper --- uncovering a private asylum where men pay to have their wives and daughters locked away, or worse. Just as Petra has reason to believe her friend is alive, a shocking murder proves that more danger is afoot than she thought.