Two people who met by chance suddenly learn that their fathers went missing as part of a 1969 geological exploration expedition in Transbaikalia. The reason for the disappearance of the expedition in those years was not established. The children of the missing geologists decide to make an attempt to find the remains of the expedition forty years later. But soon after the search begins, new acquaintances and their friends encounter a certain group of people who, by all means, including murder, are trying to prevent the mystery from being revealed. At the same time, it turns out that the true goal of the expedition was to find out the reasons for the appearance of abandoned, carefully processed granite blocks in two regions of the Amur region - the remains of some pyramidal objects similar to the pyramids of Egypt, Bolivia, China...