In the heart of Siberia, in the depths of Lake Baikal, lives a mysterious guardian of its ecosystem, the Baikal seal. This unique type of seal lives only here and is a living barometer of the health of the entire Baikal ecosystem. Every tremor of life in the submerged world, from tiny algae to schools of fish, reverberates through the fate of seals, whose influence permeates every level of nature's hierarchy.