Spring 1797.  The war with France deepens, the Channel Fleet has mutineed … and a ruthless traitor lurks within fashionable London society.  A chance encounter places an unlikely sleuth on his trail: Mary Finch. 
Having gained a fortune but lost the regard of Captain Robert Holland, she wants only to enjoy the delights of the Season, yet she cannot ignore the evidence of a deeper mystery.  Her curiosity leads to a meeting with an elusive spymaster and an audacious proposal.  With England’s security and a friend’s safety at risk, Mary agrees to become a guest at the exotic Champian Hall, to learn the traitor’s secrets from within his household. 
The assignment is a perilous one, for it aims to unmask a band of murderous conspirators who will stop at nothing to achieve their aims – and Mary has only her with and courage for protection.