How lucky the restless Veselov family - Makar, his sister Sonya and little brother Ladoshka! The city authorities decided to clean the bottom of the famous Patriarchal Ponds, which are located next to their house. But under a hundred-year-old layer of silt, real treasures can be discovered. The guys are sure that they will be able to find silver skates, or dueling pistols, or a box with jewelry from Prince Tatar, or something else unusual. But it turns out that they are not the only ones who know about the underwater secrets of the ancient ponds... And if not for the unmistakable instinct of the Veselovs’ pet, Honorik Nyuk, the scammers would have gotten the main find made on the Patriarchs. After all, everything happened so unexpectedly that at first it didn’t even occur to anyone that this little thing was a real treasure...