The Dream of the Iron Dragon

This book starts out as a surprisingly good space SF story including a page turning space chase scene involving trajectories and relativity (great stuff if you are into this sort of thing). I actually though this was the best part of the book - I'd give this 5 stars easily. Then the book takes a sudden turn. Due to the cover and blurb I don't think it's a spoiler to say that the spaceship suddenly finds itself on Earth in the 880s AD. As someone with an interest in SF and archaeology I actually really enjoyed this story. The pace was rather up and down (slow,slow, getting boring, OH MY GOODNESS SO EXCITING....slow, slow... etc.) but when it was good it was very good and I'd really like to see what happens next.