Hindmost is a Puppeteer term for any leader, especially their ruler. Since Pierson's Puppeteers are foremost concerned with their own safety and the survival of their species, the most important Puppeteer is considered to be behind, or the protector of every other member of the species. It is a shortening from the more literal the one who leads from behind. A maddened, deposed Hindmost is responsible for Louis Wu's return to the Ringworld..