A colourful banquet at the Château Perdrix is noisily interrupted by Bishop Arkwright, an American trying to spread the cause of temperance in Europe. Inspector Gautier intervenes and has the bishop expelled. Later that night Michael O'Flynn, the Grand Officier of the Chevaliers, is murdered in the hotel where both Gautier and the bishop are spending the night.
Returning to Paris, Gautier immediately finds himself in the company of Lady Jane Shelford and embroiled in another murder. Although seeming initially unrelated, the murders draw Gautier into the feuds of the temperance movement and the politics of the Burgundy wine business, where the stakes are higher than he imagined.