An overlong but imaginative entry in the revived Foundation series, with a talky opening, an intriguing middle, and an illogical fade-out. Councilman Golan Trevize, having opted for the formation of a galaxy-wide, totally empathic super-organism, Galaxia, is now having second thoughts--and his doubts focus on a possible threat from the long-lost planet Earth. So, supplied with clues by historian Janes Pelorat, and protected by the powerful Gaian woman, Bliss, Trevize begins his search. (The debate pro and con Galaxia continues, meanwhile, in tiresome detail.) In the novel's best section, they touch down on various planets, including the old Spacer world Solaria, where the hermaphroditic Solarians live in solipsistic splendor, totally isolated from each other on their vast robot-run estates, casually controlling energy by means of their enlarged brains. Finally, on Earth's Moon, Trevize encounters robot Daneel Olivaw, now 20,000 years old; Daneel, with his highly advanced brain and psychic powers, has secretly been guiding the development of Galaxia all along. And, in a total non sequitur, Trevize realizes that what he really fears--why Galaxia must be formed--is the threat of invasion by extra-galactic aliens. Dreadfully long-winded--would that the characters sometimes reply with a simple "yes" or "no"--and many longtime fans will prefer Daneel as a plain old robot-detective rather than a galactic super-brain. Yet, much here qualifies as vintage Asimov--Solaria has long been one of his finest creations--despite that disappointing, artificial finale.