In the year 700 A.D, a spacecraft crash lands in a lake, in Norway. Two space suited figures manage to get to shore and when one of them takes off his helmet we see that he's very human looking. This is because when he looks up Earth on his computer, it says "Abandoned Colony". So he's human.
He also rapidly learns the current language by injecting himself with nanoprobes, so he can speak to the local populace, who are vikings.
When the vikings ask him what he's doing in their land, he says he's hunting a dragon--and they all laugh and beat the crap out of him. But he really is after a dragon. This is a creature called a Morwyn, which had snuck aboard his spacecraft and is the reason all the crew was slain and the ship crashed. Now it's up to him to destroy the creature, but he only weapons at his disposal are swords and fire.
What I found interesting about this is that there isn't much of a culture shock for the main character, Canan (James Caviezel , as he's a soldier and can relate to these guys on some basic level. He fits right in.
The story also reminded me a bit of BEOWULF. Recommended.