Hunted, by James Alan Gardner

Apparently James Alan Gardner had intended this book to be entitled "Haunted" and it was all a big mix-up that it's called "Hunted" instead. I've thought of it as Haunted ever since I found this out, because the name "Hunted" makes actual zero sense for this book, whereas Haunted is a good name for it.

( cut for lots of spoilers for Hunted, and also some spoilers for Ascending but not much more than Oar gives you herself on the first page )