Lady Sophia's life is turned upside down when her uncle dies unexpectedly. She moves to London where she is the catch of the season, but she does her best to avoid her suitors, as she wishes to preserve her independence and control over her estate. That is until she discovers a coded note left to her by her uncle, which leads her to the very intriguing and alluring Lord Arthur Cawsey, who claims to have a long history with her uncle as a spy during the war. Lord Cawsey demands that she hands over the information to him as it may be dangerous. But he has met his match in Sophia who is determined to discover the truth. Despite their differences a fire of smoldering passion ignites between them, Sophia's life suddenly erupts into an exhilarating world of midnight adventures, as she works alongside Lord Cawsey to solve the mystery. Will solving the mystery surrounding her uncle's death also unlock the mystery of her heart?