A brilliant painting by Leonardo da Vinci - the famous Madonna Litta - has disappeared from the Hermitage of St. Petersburg. In the frame, the thief left another image, indistinguishably similar to the Madonna Litta... if not for the monstrous little monster depicted in the place of the divine child. Restorer Dmitry Starygin, who admires the work of the Italian maestro, is unfairly suspected of theft. However, the fate of the painting worries him no less than his own fate, and Dmitry flees to Rome. It was there that Professor Arseny Magnitsky worked before his death, leaving a diary with a clue as to who needed the beautiful Madonna and why. The book was also published under the title “Da Vinci’s Hell.”