In 709AD, a space craft crash lands in Norway containing Kainan, a soldier from a distant planet, who is hunting a deadly stowaway known as the Moorwen. Before Kainan can hunt down the bloodthirsty creature, he is captured by a local viking warrior and held prisoner, but after saving the life of the tribal King Rothbar, Kainan is released, and free to continue his pursuit of the Moorwen who is wreaking havoc among neighbouring clans. With everyone still up in arms, will the Moorwen succeed in destroying the viking village, or can Kainan, their only hope, use his superior knowledge to defeat the alien predator once and for all?