Unwind

Connor and Risa are Unwinds, and Lev is a tithe; their body parts are slated to be "harvested" and transplanted into people who are ill or injured. They escape, face considerable danger, are sheltered by sympathetic adults, and become part of a large group of escaped Unwinds; within this group, a destructive power struggle develops. The suspense continues throughout the story, which ends with a thought-provoking ambivalence.