BACK IN 1950 when Isaac Asimov's ". . . And Now You Don't" was published, the series of Foundation stories seemed ended and all seemed well. The universe of 12,444 G.E. (Galactic Era) was following the Seldon Plan. First Foundation was peacefully incorporating the remnants of the dead Empire, and Second Foundation, which was really running things surreptitiously, had gone underground and would presumably stay there for another 625 years or so, at which time a new millennium would break. But here it is only 123 years later, anthe Foundations are at it again.

To recapitulate for those who have not read Asimov's classic stories about social and political forces in the middle-distance future: Around 12,068 G.E., when the Empire (25 million inhabited planets throughout the galaxy) seemed all powerful and permanent, a psychohistorian named Hari Seldon announced that it was about to crumble and that there would be a chaotic interregnum of 30,000 years. Most people scoffed at Seldon, and the government exiled him and his followers to a barren planet on the edge of the galaxy. Here Seldon began his work to limit the destruction that was to come.

To shave the interregnum down to 1,000 years, he established the Seldon Plan, which was both a prediction of forces and events and a regulatory mechanism. (Just as Asimov's concept of imperial decay was based on Toynbee, Seldon's plan was based on actuarial mathematics -- one can predict certain things about large groups.) Seldon established two Foundations. First Foundation, set up openly, was concerned with preserving the hard science of the Empire and was to serve as a nucleus for a new empire. The other, Second Foundation, set up in deepest secrecy, was to cultivate the mind in terms of parapsychology and to implement the plan. The previous stories described important moments in the first 350 years or so of the interregnum.

The date is now 12,567 G.E. and a crisis is at hand. In both Foundations it is suddenly recognized that something is wrong. The Seldon Plan is working better than it theoretically should. This is disastrous, for it indicates the presence of outside manipulators, who must have their own aims and purposes. What happens after this discovery is best not revealed. Let it be enough to say that the story is a double quest and search as both Foundations intrigue and investigate, and that the problem is not really solved. The ultimate goal is to be the lost or unidentified place where humanity originated, the mythical planet Earth.

In some respects Foundation's Edge is not simply a continuation of the earlier stories, but is a redirection. A certain amount of past history has had to be rewritten, notably the career of Asimov's famous Napoleonic character, the Mule. But more important is the shift of Asimov's own position toward the ideas in the stories. The previous stories, it is now clear in retrospect, emerged from the milieu of Hitler's Germany and World War II. The Foundations were a parable on Judaism: the sacred text and its rabbinical exegetes; xenophobia; persecution; existence under cover; chiliasm and the double ghetto of the Foundations. These elements have now been minimized. The Seldon Plan is now revealed to be a fraud. The Second Foundationers, despite their paranormal abilities, are no longer pious saints but humans weighted somewhat on the down side. And the female Mayor of Terminus (chief magistrate of the Foundation Federation) is an arrogant horror. The walls, it is clear, are coming down.

After finishing Foundation's Edge I reread the earlier stories, which were published from 1942 to 1951. I probably should not have, for I found myself wishing that Asimov had waited until now before writing them. He was, after all, only 21 when he began the series, and maturity would have enhanced first-rate ideas. Foundation's Edge reveals many improvements over the earlier work. The ideas are better worked out; the plotting is better; the writing is superior; and Asimov has outgrown his tendency to trick endings that didn't always work. Instead of good guys and bad guys, we now find credible motivations like arrogance, ambition, suspicion, and feelings of insecurity -- all of which take form in manipulation. I could register a minor complaint, though, about some repetitiousness, and a stronger complaint about characterizations that sometimes do not gel. But suspense is high, and there is the usual Asimov clarity of expression. It will be an unusual reader who will put the book down unfinished.

The story of the seeker being sought, the hunter being hunted, as in Asimov's Gendibal-Trevize-Branno-Gaia wheel of fortune, has been given a new, deeper twist by Roger Zelazny in Eye of Cat.

As Zelazny tells it: Billy Blackhorse Singer, a Navajo Indian who is a celebrated Frank Buck of the future, has filled Earth's zoos with exotic life from other solar systems. But he is no longer young. He has come to realize that the Navajo world is gone and that he himself is spiritually dead. In short, a classic case of anomie. He is tormented by guilt, which he accepts as a sort of Navajo Nemesis, and this guilt focuses on one episode in his life: Years before, he captured a being that may have been intelligent, locked it up in a cage, and forced on it the same situation that he now suffers. The episode is uncorrectable, for the being's planet was destroyed when its sun went nova.

This being, Cat, now turns out to be a highly intelligent, telepathic shape-changer, filled with rage and hatred against Billy. Yet Billy must have the help of Cat in preventing a political assassination. Cat agrees to help, but its price is high: Singer's life. Does Singer really care? The novel is the story of Cat and Singer, counterparts and reverse doppelgangers of a sort, and their fracas across a world strangely blended out of future gimmickry and Navajo mythology. The plot is a hunt, but the subtext is something more profound.

All in all, this is Zelazny's finest book since Lord of Light. It offers what is expected of Zelazny at his best: stylistic brilliance, subtleties of characterization, originality, and strong mythic themes of power. My only real criticism of the book lies in Zelazny's exuberance: he sometimes overdoes it. More simplicity would have helped at times. Pages of future news headlines and paragraphs of distorto-English really do no more than throw the reader out of the story. But one can forgive these passages.

I have praised two books, but I am afraid that I cannot praise the third, Silverberg's World of a Thousand Colors. Robert Silverberg has long had two reputations. First, as a major science-fiction writer, the author, notably, of Dying Inside, The Stochastic Man, and other good work. Second, as the short-order man of the 1950s and early 1960s. At that time Silverberg sometimes wrote a short story a day and a novel every couple of weeks. He kept quite a few not entirely necessary magazines in existence. But the two reputations do not coincide, and the short-order Silverberg is not the major Silverberg.

World of a Thousand Colors contains mostly stories dashed off in this earlier period, sometimes pseudonymously, and there is not much merit among them. They include bald narratives, romantic pulp love stories, and adventure stories that barely qualify as s-f by settings elsewhere and elsewhen. These stories helped Silverberg economically when he was starting his career, but that is now ancient history. Why, when he has written so much better work, did he permit them to be republished? According to the preface he seems to like them. Well, writers can seldom judge their own work. Dickens thought A Tale of Two Cities was his best, and Shakespeare may have opted for Timon of Athens. Who knows.