@jik the other title I'm thinking of is more fantasy, being the Wind Singer

@jik it's a bit outside of your description, but it sounds like what happens when Teela eats the tree-of-life root and becomes a slightly dodgy pak protector in Ringworld. Pak protectors featurein other parts of Tales From Known Space as well, notably they have an artificial world of islands on which they stock samples of every known race, but shit is a little bit broken there.