A slick, tame sequel that extensively recaps and updates the original 2001--but betters it only in the nuts-and-bolts department. The derelict ship Discovery, with disconnected computer Hal aboard, is in a decaying orbit about Jupiter; joining a USSR/US investigatory mission are, familiar from 2001, project expert Heywood Floyd and Hal's creator, Dr. Chandra. But then, surprisingly, a Chinese ship rockets past them and lands on Europa to refuel--only to be engulfed by a plant-monster inhabiting the liquid water beneath the moon's icy jacket. And soon Discovery is operational again: Hal, his murderous memories deleted by Chandra, wakes up sane enough; of missing astronaut Bowman there's no trace; and the Star Gate (the enigmatic floating slab beyond which lurk the mysterious cosmic beings who are directing human evolution) proves impervious to analysis. Then Bowman himself, now the god-like Star Child, bursts from the Gate and heads for Earth: he is, however, still being studied by, and controlled by, the cosmic paladins who transformed him into a disembodied intelligence (where he's low man on the totem of galactic brainpower). So the Star Child pokes about Bowman's old haunts on Earth, then surveys the Jovian system--where he realizes what his masters intend and warns Floyd to leave. And, in the finale, the cosmic brains ignite Jupiter into a mini-sun, thus warming up the Jovian moons to provide the struggling Europans with a more congenial environment in which to evolve intelligence. Steady cosmic storytelling, then, short on drama but delivered with Clarke's usual boyish panache; and the many 2001 followers will regard it as compulsory reading.