An archaeologist and a detective are an excellent team for searching for ancient treasure! Namely, the twin brothers Vaska and Petya are going to find him in a monastery destroyed many years ago. But they weren't the only ones who were so smart. A certain strange company is actively bustling around in the excavation area, carrying some boxes back and forth - in general, they are behaving very suspiciously. The boys would have been watching the actions of the competing company for a long time and unsuccessfully, if at one fine moment the old ruins had not been shaken... by a powerful explosion!