In AD 922, Arab Ahmad Ibn Fadlan is sent to the land of the Bulgar's as an emissary, because he fell in love with the wrong woman. During his journey, his caravan runs into a Vikings camp. They stay the night and the next day a young boy reaches the camp to call the warriors home: The Wendol, creatures of the Mist, have started attacking their homeland, killing and eating everyone in their way. The oracle forces a thirteenth warrior to accompany the Vikings, but this must not be a man from the north. Ahmad does not feel comfortable with the strange men of the north, at first, but when he finds out that the Wendol really exist, he bravely fights alongside the Vikings in an impossible battle against an enemy that can't be stopped.