Fate of worlds2012
return from the Ringworld
by Larry Niven
A cross-over conclusion to the Ringworld and Fleet of Worlds series finds the Puppeteers of the Fleet of Worlds targeted by rival war fleets after the disappearance of the Ringworld, prompting exiled Puppeteer Hindmost to draw on his knowledge of Ringworld technology to reclaim his power.
— from OpenLibrary
4 editions at OpenLibrary