In 1676, a seemingly devoted daughter and wife, Madame de Brinvilliers, shocked all of France with the heinous murder of her father and brothers. Furious that the family disapproved of her taking a lover, she and her scurrilous paramour poisoned them out of a desire for revenge and greed for her anticipated inheritance. The ensuing scandal, skillfully recounted by noted British historian Somerset (Elizabeth I), inflamed the nation's fears that the decadent nobles at the Sun King's court were caught up in a clandestine world of sex, witchcraft and murder. Every untimely death and peculiar illness, including Louis XIV's chronic vapors, suddenly appeared to be the nefarious work of an unwholesome network of princesses, dukes and fortunetellers. As panic ballooned, even the king's mistress, Mme de Montespan, fell under suspicion (and was eventually banished from the king's bed), and many of France's most distinguished personages were sent to trial, jail and, in several cases, the scaffold. Somerset reconstructs this macabre history from surviving public documents, enlivened with contemporary gossip and wit from letters between the French elite. Her arch prose sometimes stalls amid the intricacies of myriad minor characters' histories, but overall, she offers an intelligent review of a darkly fascinating affair.