Smolensk. 1239. The richest city of Rus was supposed to meet the fate of Ryazan, Vladimir, and Suzdal—yet it stood firm against hordes of invaders, the Mongols. In legends, they will mention the feat of a newcomer warrior Mercury, who came from the future to help our past. He is a Byzantine—formerly a sea officer of an empire that has vanished. He is a warrior, and for him the battlefield is the entire history of our Motherland.