Mari, Nick and the surviving people of their clan and tribe, united into a Flock, set off on a long journey to find new lands and live there in peace and harmony with their animal companions. Many dangers await them, the main one of which comes from a terrible man who calls himself the God of Death and his minions... Meanwhile, in the distant green steppes, young River from the people of horsemen is preparing for an annual test - the main event in her life. River not only takes care of his horse, but also secretly takes care of a wild stallion nicknamed Ghost. She does not yet know that the freedom-loving horse with a silver-white mane is destined to play an important role in the fate of the people of the Herd and the Pack.