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

September, 1815. The most illustrious members of the ton are descending upon Windsor Castle for a week of celebrations surrounding the 54th wedding anniversary of King George III and Queen Charlotte.

Even better, Lady Petra Forsyth is serving as one of the four judges in a patisserie contest featuring the best cooks employed by London's finest houses--including her own cook, Mrs. Bing. Indeed, for Petra, the week is shaping up to be one of many delights, including reconnecting with Sir Rufus Pomeroy, England's most famous former royal chef-turned-cookbook author. Having begun his illustrious career at Buckfields when Petra was a child, Sir Rufus asks to meet with her while they both take part in the festivities.

Yet, as Petra goes to greet him, she instead finds a hysterical housemaid pointing to a body. Sir Rufus has been found strangled in the royal library with his own valet standing over him. What's more, the valet turns out to be Oliver Beecham, the ne'er-do-well brother of Petra's lady's maid, Annie.

In order to prove the innocence of Annie's brother--and avoid ruffling too many aristocratic feathers along the way--Petra will have to act like a lady, eat like a French chef, and think like the Royalty surrounding her. Will she be able to solve the case before her head gets served up on a platter?