Louis and his friend The Hindmost, an alien of the Pierson's puppeteer race, are prisoners of the Ghoul protector Tunesmith, a Ringworld native, who is deliberately provoking the warships that surround his world. All the star-faring races of Known Space have sent warships to the Ringworld, and they are already at the brink of war. If fighting breaks out, the near-indestructible Ringworld will be destroyed: dissolved by antimatter weapons.