On one of his trips through the nature reserve, the ranger Michailytsch found a young lynx whose mother was killed by a bear. He takes it with him to his log cabin and calls it Kunak, which means friend. The young lynx gets used to the human environment. He grows up to become a stately lynx. When he attacks a rooster one day, he is sent away. On his wanderings through the Siberian forest, he is caught in a poacher's trap. Only after a long search does Michailytsch find Kunak and frees him. But the lynx came to the attention of thieves who catch it and sell it to a circus in the city...