The Ship Who Won by Anne McCaffrey

McCaffrey continues to develop her brainship concept, with a new collaborator this time, the one who worked with her on The Death of Sleep (1990). The brainship Carialle and her brawn, Keff, find a habitable planet inhabited by an apparent mix of races and cultures and dominated by an elite of apparent magicians. Appearances are deceiving, however, and by the time the explorers have discovered the planet's secrets--not to mention other intelligent races--they find themselves in a desperate battle to save it.