About the book: year / August 1911 Leonardo da Vinci's painting "Mona Lisa del Gioconda", which is more often called simply "La Gioconda", disappears from the Louvre. It is stolen by a man who calls himself Mr. Decorator, but it is impossible to identify the thief. Meanwhile, Zagorsky and Ganzalin travel around Europe. In the Italian city of Florence, they are caught by the news that the La Gioconda has been stolen from the Louvre Museum in Paris. The painting disappeared on Monday, when the museum had a day off. In theory, this should make the investigation easier. However, the thief seemed to have disappeared along with the painting, leaving almost no traces except the protective box and the painting frame. Ganzalin persuades the owner to investigate the theft. Zagorsky seems curious about the circumstances of the kidnapping, and he decides to take on the case. Moreover, he was going to Paris anyway.