Permafrost is a commonly used scientific term. This is the frozen soil as a result of numerous glacial periods. The territory of Russia is covered by 2/3 of it. But it turned out that "eternal" does not mean "forever"... Our heroes are scientists who go on dangerous and exciting expeditions to the most diverse corners of the Russian Arctic - from Yamal to Chukotka. They are watching the permafrost melt, trying to understand its laws, to preserve it.