In this prequel to Eon, Greg Bear continues to explore the possibilities presented by the asteroid Thistledown, a remnant of a lost human civilization. The Way is a tunnel through space and time that leads to other worlds, some more like planet Earth than Earth itself. It is perhaps the most formidable discovery in Thistledown and with it come disputes as to the nature of the Way and how it should be used. The Way can be reached only through Axis City, the only space station of Thistledown.

At first, only a few things are known about the celestial object that astronomers dub Rama. It is huge, weighing more than ten trillion tons. And it is hurtling through the solar system at inconceivable speed. Then a space probe confirms the unthinkable: Rama is no natural object. It is, incredibly, an interstellar spacecraft. Space explorers and planet-bound scientists alike prepare for mankind's first encounter with alien intelligence.

Welcome to Ringworld, an intermediate step between Dyson Spheres and planets. The gravitational force created by a rotation on its axis of 770 miles per second means no need for a roof. Walls 1,000 miles high at each rim will let in the sun and prevent much air from escaping. Larry Niven's novel, Ringworld, is the winner of the 1970 Hugo Award for Best Novel, the 1970 Nebula Award for Best Novel, and the 1972 Ditmars, an Australian award for Best International Science Fiction.

The Mote In God's Eye is their acknowledged masterpiece, an epic novel of mankind's first encounter with alien life that transcends the genre. No lesser an authority than Robert A. Heinlein called it "possibly the finest science fiction novel I have ever read".

On September 28th, a geologist working in Death Valley finds a mysterious new cinder cone in very well-mapped area. On October 1, the government of Australia announces the discovery of an enormous granite mountain. Like the cinder cone, it wasn't there six months ago.

Something is happening to planet Earth, and the truth is too terrifying to contemplate