At the beginning of winter in 1889, mounted on Serko, his small, grey horse, Dimitri leaves the Amour river, situated on the eastern borders of the Russian Empire, and sets out on a journey. After extraordinary adventures, they both arrive in Saint Petersburg, at the Tsar’s court. Having covered 5,600 miles in less than 200 days, this young horseman and his horse have thus achieved the most amazing equestrian feat of all time.