Some years ago the Main Deep Sanitary Sewer had been constructing in Saint-Petersburg. And Mutabor, Lanivs and Megavolt had decided to visit it at the night before the Victory Day. At the construction area everything was quiet: workers were at vacations, the night watchman was sleeping. The friends succesfully went down through the shaft and started exploring the freshly built sewer which indeed was like a huge tunnel. At the beginning the tunnel was just constructed, with construction machines in it and than it had become more and more finished.