Maxim Serov is a doctor taking part in the ISS mission together with his partner, Mikhail. The ISS flies through an eerie glow and ends up above Earth—where the outlines of the continents are the same, but there are changes. Most of all, there’s no connection with Mission Control, and there are no traces of human presence on the Earth’s surface. Maxim’s partner dies, and he decides to land on an uninhabited and wild Earth. But Earth is not completely uninhabited, and soon our cosmonaut will be able to meet both Cro-Magnon people and Neanderthals. What else can an ordinary Russian guy do, besides bringing the light of knowledge to these people?