Bridgerton meets Agatha Christie in this dazzling fourth installment to the captivating Regency-era Lady Petra Inquires mystery series.

London, December, 1815. It's Christmastime, and Lady Petra Forsyth is concentrating on behaving herself. Thus, she's 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, splayed below the ballroom's balcony. 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. Indeed, it's enough to make an obstinate, headstrong girl scream.

As she begins to unravel the truth, all while pretending to flirt with the bachelors to keep her cover, Petra will need to act like a lady-a Lady Patroness, that is-think like an enterprising scientist, and use every lock pick and defensive move she has learned to ensure that her reputation-and her life-don't become the next target.