The protagonist of the story is Artem Kharlamov, a 30-year-old private detective who works undercover for the FSB. Upon the advice of an old friend, he is approached by an elderly bookseller for help. The bookseller has received an order from another country for a rare book from the private collection of Marshal Ney, one of Napoleon Bonaparte's famous followers. However, the bookseller fails to mention that the book contains a cipher that reveals the location of the French conqueror's lost treasury, which went missing in the Russian Empire in 1812.