January 1774Commissioner Le Floch's lover, socialite Julie de Lastérieux, is found murdered in her bed, a victim of poisoning.Nicolas retains the confidence of those closest to him, and is even sent by Louis XV to London on a secret mission. But a plot is afoot to implicate Le Floch in Julie 's death, and he faces the toughest challenge of his career as he fights to clear his name and bring the real murderer to justice.