At the heart of this episode, without forgetting Lake Baikal's nerpa seal, the Volga's cranes, or the rare Caucasian bison, is a study of one of Russia's most important natural resources. From the shores of the Volga to the depths of lake Baikal, and to the thousand rivers of the Caucasus, Russia has a supply of incalculable wealth; water. In a world that faces water shortages, Russia's blue gold has become a precious natural resource.