Basileus Justinian II was overthrown from the throne, his nose was cut off and he was sent to prison in the distant Crimea. Having escaped from custody, Justinian vows to take revenge for his shame not only on the usurper of the throne, but on all his former subjects. He leads a mercenary army into the empire, led by a squad of northerners, the invincible Vikings of Mstveld, and the cavalry of the Bulgarian Khan Tervel, the son of the famous Asparukh. The Slavic warrior Lyubenya also swears an oath to the gods - to take revenge on the kidnappers of his beloved and find her alive or dead. He joins the Vikings and fights in Byzantium, searching for the girl. Will the warrior be able to find her? Will the basileus' troops be able to take the impregnable Constantinople by storm?