Fast-moving 18th-century adventure/romance--French Revolution, double-Dutch mysteries, squirmy grue--by the author of the splashy A Crowning Mercy (1983). Lady Campion Lazender is the only family left to tend to her father, the fatally ill Fail. Her brother Toby is in Paris, ostensibly a civil servant at the British Embassy, but really a top agent for brilliant (if gross) spy-master Lord Paunceley--who relishes plots, counter-plots, and grisly hangings. Their cousin, next in line to the title, is Sir Julius Lazender, a weak and unsavory sort who gambles and whores in various London stewpots. And this odd family group also includes Campion's cheery Uncle Achilles, whose father--the (fortunately) departed Mad Duke--built a shrine to himself at his Chateau Auxigny in France. Thus, things get complex for the Lazenders once the Revolution is in full bloody swing. First of all, a weird collection of fanatics who call themselves ""the Fallen Ones"" (each has the name of a fallen angel) meet, masked, at the Mad Duke's chateau: ""Lucifer,"" the boss-killer, is plotting to get guerrilla funding from assaults on the Lazenders. Meanwhile, over at the family's English estate, there are strange visitors: oddly fascinating ""Gypsy"" Gitan, Toby's Romany groom--who take secret orders from the Fallen Ones; and handsome Major Lewis Culloden, who rescues Campion in the nick of time from rape by a seedy ruffian. Moreover, cousin Julius is--for shady reasons--being allowed to run up a huge debt at his favorite brothel and gambling hell. And Toby, spying for England, is betrayed and reported killed (to Lucifer's glee) in France--while Campion, who marries Lewis just before her father's death, learns some awful truths. Complete with a gory finale at the chateau and flip-flop revelations: smartly paced shocks and dangers--as Kells slaps her red herrings around with well-costumed gusto.