Maksim Serov ends up in the Stone Age of a parallel universe right from the International Space Station. He adapts, finds the first people, founds a settlement, and by uniting three tribes, creates a powerful tribe of the Rus’. The Rus’ repel the rapid assault of a strong enemy— a large horde of savages migrating from Africa to Europe. Maksim improves his tribe’s everyday life using knowledge from the 21st century. Life gets better—until a World War II-era military aircraft crashes down near the settlement of Plazh. Americans! Friends or enemies? And what else awaits our hero on the path to organizing the first state of the Stone Age?