A letter from Lady Georgiana Rannoch’s best friend, Belinda, heralds a trip to Paris to visit her. Darcy has a spot of business of which to take care, so Georgiana will be staying in Belinda's flat as she works feverishly on Coco Chanel's fall collection. When Darcy asks her to covertly retrieve something from an attendee of Coco's show, this little errand could have terrifying consequences for a world on the brink of war.