Set on and above a future Earth that has been ravaged by various factors (population decline, volcanic eruption etc) this has a cast of both primitive (ish( and scientific people. The main lead is Car-En, an anthropologist from the Ringstation circling the Earth. She is on her first field assignment and is watching a viking-like village (especially a handsome hunter). When the sister of Esper (he's the hunky hunter) is abducted by someone who shouldn't be there she decides to take an active role instead of the passive observing role she should, cuts off all contact and sets off to follow and hopefully rescue the sister. This may have dire consequences for her career but I'm thinking you've guessed that already.
To be honest, on finishing this book I still don't know whether I enjoyed it or not. It wasn't a bad story although it did feel a bit 'flabby' in places. The mix of Sci-Fi and fantasyesque settings and characters felt a bit of a mish mash in places but the ideas weren't as bad as I thought they would be.
I guess the best I can say is that I'm sure many will Enjoy it but this story just wasn't for me which is a shame.