By the author of the noteworthy fantasy The Dragon Waiting (1983), a coming-of-age yarn set on the Moon a hundred years from now. The problem for young, talented Matt Ronay and his friends is the lack of new horizons: Earth is despised and feared; the colony worlds and space habitats seem like dead-ends; only the starships offer a chance of escape--but that chance is minuscule. Matt accepts an offer to join an acting company, while planning an illicit outing with his friends to the far side of the Moon; his father Albin, meanwhile, wrestles with the problem of providing water for the Moon's insatiable population while avoiding becoming indebted to the Earth and the predatory VACOR corporation. Matt and friends--they're heavily involved in a role-playing, virtual- reality game--depart on the lunar train; during one of their stopovers, a VACOR saboteur ignites a riot by playing upon existing antipathies toward starship crews; by chance, Matt is able to help the crew at the center of the riot escape, then is offered a place on their starship. He seizes his chance, knowing that his mother, an ``exosurgeon,'' can provide him with the artificial nerves and sensory boosters he'll need in his new life. A carefully constructed, sometimes brilliantly imagined backdrop, but the characters remain lifeless; and Ford's hints and allusions are no substitute for a solid plot. Fair to middling work that promises more than it delivers.