A human expedition into deep space encounters a gigantic artifact—a bowl-shaped object with a star at the center, and a habitable area equivalent to many millions of times the Earth’s surface. A landing party is sent to investigate, and they find a variety of strange, exotic creatures populating the Bowl. The landing party is separated into two groups—one is captured by the alien inhabitants, the other is pursued across the exotic and deadly terrain.

This is the first collaboration between two modern masters of science fiction.