Petra Rebovka aka Louise Charrière, an operational officer with the security services, travels on her first assignment to the Limousin region of France to infiltrate a people trafficking operation. In the guise of a student, she arrives in Limoges to work undercover. Her main contact is Jean-Marie Fauchet, a retired ex-gendarme. He assists her to meet Alexis, a potential informer who, not only leads her inadvertently into danger, but also forms a romantic liaison with her. His Russian grandmother befriends Petra and reveals a secret linked to the Russian revolution and kept hidden for almost a century. Fascinated by the old woman's reminiscences, Petra resolves to discover the truth. An investigation into the deaths of two young French males in the U.K. brings Petra into confrontation with her old adversary, Detective Chief Inspector Massey, who arrives in France accompanied by a colleague. Clashes of personality and previous antagonisms hinder the inquiry until the action moves to Marseille. Petra and her detective colleagues are forced to put aside their differences to prevent the success of a plot to send Al Qaeda-trained suicide bombers to the U.K. A raid by the security services at the villa of Michel Dumas, a wealthy businessman suspected of involvement with terrorist activities, places Petra and the English detectives in danger. Petra is confused by the main aspects of the investigation and the roles of the participants in the security operation. Though masquerading as a student under an assumed name, she is determined to discover the truth about the assignment, the radical views of Alexis and the incredible ramblings of his grandmother. Once again, the mystery surrounding Nicholas II, the last Tsar of All the Russias, threatens to rewrite history. Added to this, the imminent threat of terrorist activity in the U.K. causes unexpected twists and turns in the outcome of Petra's journey of discovery