V century n. e. Europe is going through the most terrible times - the Great Migration. Hordes of barbarians threaten Roman civilization. It seems that the end of the world is approaching, and for some tribes, exterminated to the last man, it really has come. It was at this time that Attila became the ruler of the Huns. In the summer of 452, he began a campaign in Italy, against Rome. The Eternal City cannot defend itself by force of arms, but it still has someone to rely on - the Roman Pontiff Leo, not only a church leader, but also an excellent diplomat. Leo decided to go to the camp of the ruler of the Huns and do the impossible - to convince Attila to abandon the conquest.