I read it in the early 90's, in swedish. But probably translated from English and from 70's or 80's. A hardback not too thick, maybe 250 pages and all I remember of the story was that it started as some kind of historical/fantasy story set in a hunter/hutliving kind of society. A boy and his father travels for some reason, something is threatening their society. They travel by running and they are some sort of runners. And soon it becomes clear to the reader that its an actual sci-fi story and some spaceship or old technology is hidden in their world. Could be that the people are even remnants of space farers coming there long ago. This is all from long ago so I can be wrong on the details. I would say the book was part of some sci-fi bookclub or series, like sci-fi masters or something.