Hero Jarvis, reform-minded daughter of the Prince Regent's cousin, enlists Sebastian St. Cyr's help in investigating the brutal murders of eight prostitutes by a killer whose ominous plot threatens to shake the nation to its very core.

In 1811, murder has jarred London's elite. The sons of prominent families have been found at dawn in public places, their bodies mutilated and strange objects stuffed into their mouths. Although Sebastian St. Cyr is distracted by his seemingly doomed relationship with actress Kat Boleyn, the oddness of these murders nags at him — and he becomes determined to track down the assassin, even at the risk of his own life.

The young wife of an aging marquis is found murdered and wearing a necklace said to have been worn by Druid priestesses — that is, until it was lost with its last owner, Sebastian St. Cyrs mother. Now Sebastian is lured into a dangerous investigation of the marchionesss death — and his mothers uncertain fate.

It's 1811, and the threat of revolution haunts the upper classes of King George Ill's England. A beautiful young woman is found savagely murdered on the altar steps of an ancient church near Westminster Abbey, and the dueling pistol found at the scene and the damning testimony of a witness both point to one man — Sebastian St. Cyr.