The Mote In God's Eye
In the year 3016, the Second Empire of Man spans hundreds of star systems, thanks to the faster-than-light Alderson Drive. No other intelligent beings have ever been encountered, not until a light sail probe enters a human system carrying a dead alien. The probe is traced to the Mote, an isolated star in a thick dust cloud, and an expedition is dispatched.
In the Mote the humans find an ancient civilization - at least one million years old - that has always been bottled up in their cloistered solar system for lack of a star drive. The Moties are welcoming and kind, yet rather evasive about certain aspects of their society. It seems the Moties have a dark problem, one they've been unable to solve in over a million years.
Related: The Gripping Hand (Larry Niven & Jerry Pournelle, 1993), Outies (J.R. Pournelle?, 2010)
Wikipedia, Worlds Without End
, Richard Harter
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