How important are animals that belong to the very top of the food chain? The animals who do not fall prey to anyone but only hunt others. In the 1960s, several young environmentalists began research in different parts of the world: the Amazon jungle, the depths of the Arctic Ocean, the heart of Africa and the Pacific coast. The group proposed a revolutionary theory: there can be no diversity without predators. Fifty years later, evolutionary biologist Sean Carroll wrote a book based on this ingenious adventure called The Serengeti Rules. This beautiful story of how several enthusiasts were able to change our understanding of ecosystems, lacked only a vivid illustration. Now it has that. The Serengeti Rules is probably the most beautiful film at the Festival this year. In terms of visual aesthetics and complex cinematography, it is on a par with BBC's famous series about nature. Perhaps it is the most optimistic film in the program as well since in the end we learn that what we have done to nature is partly reversible.