Fans of both hard and softer, psychological SF will welcome veteran Niven and newcomer Cooper's well-written tale of a 60,000-year layover in space, in which physical challenges of world building are matched by social challenges of collaboration among disparate groups. After arriving in an inhospitable solar system, the Earth Born, colonists on an interstellar journey, need to refuel their ship, John Glenn
, with antimatter. Since they lack laborers, the Earth Born construct a moon where they can build a particle collider and raise a work force, the Moon Born. Destined to be abandoned, the Moon Born struggle to gain as much knowledge and technology as they can before the Earth Born depart. Some of the technology includes artificial intelligences, whose unrestricted use caused the Earth Born to flee Earth in the first place. Niven and Cooper provide complicated characters, particularly the AI, which struggle with realistic moral dilemmas. If the novel loses a bit of its emotional credibility in a compressed climax, it errs on the side of telling a rich story completely in a single volume. Agent, Eleanor Wood
. (June 14)
