Why Kings Confess - Sebastian St. Cyr Mystery

Regency England, January 1813: The mutilated body of a young French doctor found in an alley beside a mysterious, badly injured woman entangles Sebastian in the deadly riddle of the “Lost Dauphin,? the boy prince who disappeared during the darkest days of the French Revolution.
 
Thrust into dangerous conflict with the Dauphin?s sister—the imperious, ruthless daughter of Marie Antoinette—Sebastian finds his self-control shattered when he recognizes the injured woman as Alexi Sauvage, a figure from his own past associated with an act of wartime brutality and betrayal that nearly destroyed him.
 
With the murderer striking ever closer, Sebastian fears for the lives of his pregnant wife, Hero, and their soon-to-be-born child. And when he realizes the key to their survival may lie in the hands of an old enemy, he must finally face the truth about his own guilt in an incident he has found too terrible to consider....