Former employee of the Israeli military prosecutor’s office, and now the owner of a detective agency, Elina Kogan arrives in Saint Petersburg for her friend Professor Ninel Nikolaevna Astakhova’s anniversary. There she meets Bogdan Apostolov—her beloved person, who once betrayed her and is now seeking reconciliation. Returning from a restaurant to the hotel, Elina picks up in a taxi a small sheet with a graphic impression and text in French. The taxi driver explains: in the car before her, two slightly drunk men were riding—he picked them up from a collectors’ club. All the way, they argued about the authenticity of the letter. The owner of the rare item insisted the letter was written by an officer of Napoleon’s army. Another argued it was a forgery because in the autumn of 1812 Napoleon’s army was fleeing, and its postal services were inactive. In an attempt to return the rare item to its owner, Elina and the driver go to his home and see him fall out of a window. Elina asks Bogdan Apostolov for help. When they learn that the second taxi passenger has disappeared, they realize they have an опасний document in their hands. At the same time as the police, Elina and Bogdan carry out their own investigation, during which they face invisible but powerful opposition. In reality, this mysterious story began back in 1812 near the Nesvizh Castle—an ancestral estate of the Radziwill princes. There, two officers of opposing armies became involved in the disappearance of sacred relics—the golden apostles from the Radziwill princes’ treasure rooms.