In this first collaboration by science fiction masters Larry Niven (Ringworld) and Gregory Benford (Timescape), the limits of wonder are redrawn once again as a human expedition to another star system is jeopardized by an encounter with an astonishingly immense artifact in interstellar space: a bowl-shaped structure half-englobing a star, with a habitable area equivalent to many millions of Earths…and it's on a direct path heading for the same system as the human ship.

A landing party is sent to investigate the Bowl, but when the explorers are separated--one group captured by the gigantic structure's alien inhabitants, the other pursued across its strange and dangerous landscape--the mystery of the Bowl's origins and purpose propel the human voyagers toward discoveries that will transform their understanding of their place in the universe.