Jack Vance 
Pnume [EPUB ebook] 

The Pnume were an ancient race of the planet Tschai, living underground in a vast network of caverns with their human slave-species, the Pnumekin: The Pnume were the historians of Tschai, collecting its past with ruthless and scholarly dedication. Surface-dwellers never saw the Pnume — if they were lucky. Adam Reith was not so fortunate. The Pnume had heard rumors of a strange man, claiming to have come from the planet Earth, and they wanted him for Foreverness, the museum of Tschai life. Adam Reith was about to become an alien exhibit.