The End of Eternity by Isaac Asimov
Hardcover: Doubleday, $2.95, 191pp, 1955
Like Pebble in the Sky, The End of Eternity is another novel with an alternate version (in this case, a prior novella) in The Alternate Asimovs. I’ll cover both, beginning with the most familiar.
The central organization in this temporal novel is Eternity, which had its genesis in the 24th century as a result of Vikkor Mallanssohn’s work on Temporal Fields, though it wasn’t until the 27th that Eternity was founded as a organization outside time which facilitated trade up and down the timeline of Reality. (Depending on orientation, Eternity can be seen as a giant corridor or elevator where Eternals on one side live and work at the stations of different centuries and, on the other, can pass into the Timed realm of those centuries.) Later still, Eternity became more and more focused on Reality Changes, though this second aspect was kept hidden from the “Timers” within the ever-fluctuating timestream the Eternals manipulate. They would be disturbed to know that, as in one extraordinary scene, an Eternal using the principle of Minimum Necessary Change can move a container from one shelf to another to destroy a technology, kill millions, create millions, and alter the personalities of millions more. After fairly modest beginnings even as Changers, Eternity created access to the far future, tapped into the power emitted by the Sun, which will somehow go nova, and is now powered by Nova Sol and has access to all Time, excepting only the 70-150 Thousandth Centuries in which Eternity exists but out of which Eternals cannot pass into Reality. And, after that, there are no humans in the higher centuries anyway.
Eternity is also a bureaucratic organization. Eternals must be drawn from Timers (usually at the age of 15), spend ten years as Cubs, before becoming Observers (who actually go into Time and bring back data), before finally becoming Specialists which, among other things, may mean Computers (those who compute the Reality Changes), Plotters (who determine the nature of analogous people after Changes), Sociologists (who study societies generally), or Technicians (who determine the methods and then implement the Changes – and who are ostracized by the others much as judges are admired and hangmen are are not – scapegoats for the “collective guilt involved in playing God”). Those who fail become Maintenance though, without them, Eternity could not function. Eternals are also not allowed to marry or reproduce and must have even temporary liaisons submitted for approval.
The Eternal the book focuses on most is Technician Andrew Harlan, a 32-year-old native of the 95th Century who recently worked in the 482nd Century but is now primarily based in the 575th Century after attracting the attention of Senior Computer Laban Twissell, the most powerful member of the Allwhen Council, and being transferred there to work with him. The engine of the plot began before the story opens, when he received his first assignment as an unsupervised Technician, though still under the authority of Assistant Computer Hobbe Finge who increasingly dislikes him. Harlan returns the favor when his puritanical morals are offended (and his jealousy stoked) by Finge’s new secretary, Noyes Lambent, a Timer from the 482nd Century who is a sexually liberated and barely clothed aristocrat of a hedonistic society with matriarchal elements. This brings out much psychosexual conflict (though it turns out Finge has other motivations) and, when Harlan is assigned to observe from her home in the 482nd and ends up sleeping with her, one result of this is a feeling of victory over Finge but another is that he decides he must continue this relationship with her, Eternity be damned if necessary. The night he slept with her, he also had an insight into a secret about Eternity that he believes gives him great power so that he can force them to let him have Noyes.
Meanwhile, Twissell has assigned Harlan, who has an interest in Primitive history (the time before Eternity) to teach this history to Brinsley Sheridan Cooper (a new Cub, unusually old at 24, who was even married in his time of the 78th Century) as Cooper is being prepared for a special mission which is critical to the existence of Eternity. Harlan’s connections to Noyes and Cooper come together when a Change will erase Noyes, he pulls her from Time and takes her “upwhen” where they stop at the 111,394th Century, which is in the Hidden Centuries. He intends to hide her there until he can work out something better but, on a return visit, he finds he’s blocked at the 100,000th Century and, thinking Finge may be responsible, returns to violently confront him. One thing leads to another and Harlan is prepared to sabotage the Cooper mission when revelation is followed by revelation and Harlan’s intent is changed again and again.
Aside from the story and its technical execution, there are a couple of particularly interesting conceptual elements to this (aside from, obviously, the quietly awe-inspiring concept of Eternity, itself). The most isolated is the character of Noyes Lambent. There are aspects in which she’s the girl of one’s dreams and a sort of trophy, at least in part of Harlan’s mind, but his puritanical disapproval (driven by sublimated lust) is broken by actual contact with her and, while he suffers from some virgin excess and aspects of the romance both ways strain credulity, she is ultimately an independent woman. This (complete with bedroom scene) is remarkable coming from the previously almost sexless Asimov writing in 1955. Later, Harlan wants to ask her about previous relationships but doesn’t when he attains a new perspective about her different background: “He might as well ask a girl of his own homewhen if she had ever eaten in the presence of a man and how dare she?” This might not be impressive to some now (or maybe it would be, with aspects of a New Puritanism creeping in) but, in terms of 1950s science fiction, this seems to me to be an extraordinary depiction of a “liberated” woman.
Even more interesting, but tied to extrinsic things, is the comparison of this with its prior version and with the Foundation series. In ways, Eternity is to Time as Foundation is to Space. Given the insignificance of Gaal Dornick’s character, Seldon essentially stood alone, whereas Harlan and even Cooper have relatively more prominent roles but Twissell (despite the poor name) is something of a Seldon figure. Much is made of Heinlein’s garrulous know-it-alls such as Lazarus Long but Asimov also seems to have had his own icon of a wise old man of deep technical prowess. Also, like Heinlein, you can’t necessarily read too much into it in a simplistic way, as the Seldon of the Foundation and the two Twissells are all three portrayed with very different moral evaluations. Moving to the organization itself, “Harlan liked to think that Eternity was like the monasteries of Primitive times,” and both the Foundations and Eternity have something of the medieval cloister to them. Both have a public front of commerce or academia but, behind the scenes, they really shape and mold humanity for good or ill (making foreknowledge a problematic thing). And that’s precisely one of the more interesting things: Asimov usually sees this as good, but not always. This book wrestles with the notion of beneficial and harmful technologies (whether mass duplicators, “atomic wars and dreamies,” or space travel), the costs of promoting or suppressing one or the other, whether one can sensibly choose one’s own adventures and whether this will help or harm the species (raising again Asimov’s nightmare of “blind alleys”), what “the good” in life is, and perhaps fails to wrestle with, but implicitly raises such issues as how one can have diversity in an empire or cohesion in chaos.
As interesting as all that is, as compelling as some of the characterological and conceptual drama is, and as unusual a time travel book as this is (with few paradoxes and little actual travel in Reality), it does suffer from some of the ills that time travel fiction is heir to. Though there is a reason for the Hidden Centuries, there are other limits in time and space to this shaping of Reality which are not explained and it certainly seems like there would be an easier solution to the entire dilemma of Eternity than what is actually applied. There are structural issues such as the narrative POV’s poor handling of Harlan’s frequent reveries in subjective time about his real past (as in the scenes with Voy in at least Chapters 1, 6, and 10) which even leads to his discovering something about Noyes twice and, probably due to the expansion from the novella, there are a couple of flabby chapters including 6. Even more significantly, chapters 12, 15, and 17 have contrived elements regarding Harlan’s actions for and against Eternity and an action toward him, as well as an issue—though it ends up not mattering—that Cooper should be puzzled about after his trip to the past. The fact that it doesn’t matter is yet another problem, as this suffers from what might be described as Chekhov’s bazooka or a red whale-herring, though I can’t get into it (or most of the problems) without spoiling the surprises.
All in all, this is an audacious and interesting book and I certainly wouldn’t advise anyone to avoid it, but I can’t fully recommend it to the general reader, either. Asimov fans or time travel buffs basically have to have it, though. 
As The Alternative Asimovs details , this all came about on November 17, 1953, when Asimov was in the Boston University library looking over old issues of Time and saw what looked like a mushroom cloud. Though it turned out to be a line drawing of Old Faithful, he started wondering about how it could have come to be if it had been a mushroom cloud and, from December 7, 1953 to February 6, 1954, he wrote what he came to see as a “dehydrated novel” which he could not get anyone to accept. Finally he gave it to his book editor and asked if there was potential for a novel and the editor said there was, so he rewrote it from April 21 to December 5, 1954. Even that could not find anyone to run it as a serial, so it came out in book-form only.
Unlike the relatively mild changes to “Grow Old Along with Me”/Pebble in the Sky, the differences in these two versions are extreme, though there are minor differences as well. For instance, Andrew Harlan was originally named Anders Horrem and Vikkor Mallansohn was Harvey Mallon. Harlan and basically everyone else are a few years younger and sometimes come from different centuries. More significant changes include the elimination of some people and ideas.  Even the essential plot, until elements of the end, are about the same (though the major element of the Hidden Centuries was missing). However, in the original, Horrem is a sort of villain and Cooper is a much more important character (who almost disappears from the novel) while Noyes is a significant plot motivator but minor character. Even beyond that, the story doesn’t wrestle with the definitions of “improve” or “the good” and the entire philosophy and conclusions of the two versions are diametrically opposed.
The effects of some of these differences are to make the original much more concise (obviously) with some stronger scenes (such as the container-switching scene) but also more coherent in plotting, though at the cost of diminishing the still huge scope and being less focused on central characters. It also produces odd fallout where, in the novel, the reduction of Cooper’s character and his interactions with Harlan versus those with Manfield make the psychological profiling for communication methods at the end even less convincing. On the other hand, the ending to the novel is vastly stronger than the parts of the two-step ending of the novella combined. I was pleased to note that even Asimov admitted in the Afterword, “I was amazed I had made the ending as weak as I had.” So, in ways, the novella is initially stronger but ultimately pales in comparison to the novel.
There are a couple of funny things about this, though. One is that having two versions of The End of Eternity is perfectly fitting, as Asimov simply worked a vast Reality Change on the story just as happens multiple times within the stories. Also, the two versions make this perhaps the first example of Asimov’s revision of a work to hew closer to the One True Series, a process which came to a climax with the mid-80s novels. Some changes are made to relate this to the Foundation universe and an Afterword at the end of Foundation’s Edge implies this is officially “in universe” though this is abandoned for the list in the Author’s Note in Prelude to Foundation.
Ultimately, I think this novella has an amazing concept and is generally well-executed and has several characters with compelling backstories but the underwhelming ending and deflating twist don’t do justice to the material. I wouldn’t have wanted to reject it and certainly wouldn’t have wanted the total revision that Gold did, but I would have wanted Asimov to write a better ending. I find the novel version superior and the novella version is probably only of interest to major fans or writers but, due to its differences, it’s of more interest to those major fans than even “Grow Old Along with Me.”
 It’s my impression that it’s a well-regarded novel and that I’m in a minority of the less impressed but Asimov, himself, says “I do consider it underappreciated, however, and feel it is unfairly drowned out by my Foundation novels and my Robot novels. Someday, after I’m dead perhaps, it may come into its own.”
 For instance Cooper’s teacher, Manfield, disappears, with half of his character being given to Harlan and half to Twissell. A character named Attrell is deleted along with his interesting perspective that “The last millennium of Primitive times was a kind of straight-line development with a steadily developing technology,” but “You’re going to find out the human pattern of history isn’t a line; it’s an irregular sine curve… A given era is just as likely to be similar to your own as different.”