Bear is such a superb science fiction writer that even his not-so-good novels are better than most of the stuff shelved in the colourful section of the bookshop. City at the End of Time is too long; or to put it more precisely it’s long in the wrong places and too short when it could have unpacked itself. But it held my attention right to the end, and I came away if not wholly convinced then at least dazzled by the jewels embedded its suet-texture. Some portions are dull, some of brilliant, and only one aspect is unforgiveable. Unfortunately for me the novel ends with this aspect, but others may be more forgiving. I’ll come to that in a moment.
So, yes, there is, as the book’s title leads us to expect, a City at the End of Time: the Kalpa, it is called. It’s a nicely presented conception, actually: a cool 1930esque-futurist giant edifice protected from the surrounding chaos, or unreality, by ‘an outward phalanx of slowly revolving spires, blurred as if sunk in silt-laden water: the Defenders, outermost of the city’s reality generators’ . This is a likeable fictive notion, I’d say; that reality can be generated and maintained, like an electromagnetic field, against the entropic assaults of unreality. In this city we meet various elevated godlike beings, and a couple of ordinary coves, who, it transpires, after a good deal of novelistic throat-clearing, must leave the city and trek through the unreality outside to another city, for complicated reasons about which I remain slightly hazy.
Then there’s the other half of the novel, set in our world at our time (more or less). Three youngsters, Ginny, Jack and Daniel, each in possession of a mysterious stone in a box and each with unusual abilities w.r.t. the fifth dimension, gather in a Library against the encroachments of the Chaos that is devouring the cosmos—the same Chaos that the Kalpa’s reality generators hold at bay. Chaos in this novel is called Typhon, and is marshaled by the White Goddess—the Chalk Princess, Bear calls her, which I don’t think will please her (a princess is hardly the same rank as a goddess, after all):
Her face [was] illuminated from within like a lantern. Skin white as ice, eyes silver and gray and green, her body lost in something that wrapped her like a map of golden rivers and green fields—limbs long, graceful 
There’s another force at odds with Chaos, creative rather than chaotic, and this Manichean cosmos of branching realities provides the environment in which our three protagonists hop from fate-line to fate-line. Libraries protect against the chaos because … well, because of various involved explanations dumped-in at various places, but actually because Bear really likes books. That’s OK. He’s a writer, and reader, and is entitled to like books. I like books too. Books are one of two things, actually, that Bear really really likes. I’ll come to the other thing in a moment; but for now it’s enough to say that these two things that Bear really likes are the two things most widely prized amongst science fiction fans. Which may well endear the book to Bear’s natural constituency. Anyway: the books in Bear’s book shift and shuffle their meaning, with word-spiders crawling between the lines.
Language is as fundamental as energy. To be observed the universe must be reduced—encoded. An observable universe is a messy place. Language becomes the DNA of the cosmos. 
There are infinite libraries in this novel, which of course makes us think of Borges; neatly, Bear sets the novel in a reality in which Borges is an imaginary character known only from his name in a bookplate in a rare edition held in the British Library.
So these three characters, Ginny, Jack and Daniel (there’s a rather Enid Blyton vibe about those names, don’t you think?), chased by sinister agents, get themselves caught up in some rather-too-leisurely adventures. They meet up with some frankly disposable other cast-members—a coven of twenty-first century wine-bibbing middle-class sort-of-witches is particularly wincing. We realize that their fates are intimately connected with the characters in the city at the end of time. There’s a lengthy build-up to these latter characters’ trek through the Chaos outside the city; and although, when it finally comes, it’s fairly cool, the weirdnesses Bear describes is a little anticlimactic. I was reminded, and not to the novel’s advantage, of the Beatles ambling through Pepperland, or—indeed—of Spongebob and Patrick trekking through the oceanic trench and past one-eyed Cyclopes (‘Bigger Boot!’) to recover King Neptune’s crown. It is very much enormous faces looming up over the horizon, weird lifeforms scuttling past on many towering legs, buildings made-up of lots of bits of famous buildings, museums where a million iterations of yourself are trapped inside a vast block of Perspex, and so on. It only intermittently generates a properly estranged mood. To be honest, I began to lose interest in what happened to Ginny, Jack and Daniel a way before the end of the novel. But there are plenty of redeeming touches of genius. I was, for instance, very struck by this account of the infinite-branches of alternate reality lines:
An infinite lattice of branching and debranching lines, each capable of producing another lattice—you’d think that would be totally intractable, but the secret is, the branches don’t last—they sum to the least energy and greatest probability, the greatest efficiency. [Daniel] said something so utterly brilliant it was stupid. He said, “Dark matter is stuff waiting to happen…”
Isn’t that last statement lovely? I also loved the way Bear can focus the sense-of-wonder that is, otherwise, too diffusely spread through the novel into smart, dazzling little future-histories.
Once … humans had thought the universe might last no more than a few tends of billions of years. No one in the brightness—the warm, brilliant womb of the last trillion centuries—could have guessed how long history would drag on … As for the late Trillennium, in the shadow of the Chaos: broad legends described the age of the Mass Wars. Bosonic Ashurs had returned from their mastery of the dark light-years, seeking ascendance over all—and were subdued by the mesonic Kanjurs, who in turn were defeated by the Devas, patterned from integral quarks. Devas were then forced to give way to the noötics. Noötic matter was hardly matter at all—more like a binding compact between space, fate and two out of seven aspects of time. The noötics—calling themselves Eidolons—gathered survivors from the last artificial galaxies and forced nearly all to convert. [213-14]
More of this, and less tedious faffing around a disintegrating Seattle, and I would have fallen properly in love with this novel. As it was I hovered on the edge of inamoration. But then I read the end of the book, and my face fell. The book left a very unpleasant taste in my mouth—or, perhaps not taste exactly; but certainly texture. The texture of furballs.
I mentioned earlier that there are two things that Bear, evidently, loves deeply; and that these two things are passions he shares with most of science fiction. One of passions I share: books. The other I have a violent and increasingly deep-bedded antipathy towards. Unfortunately—for me, although probably not for most SF fans—the second of these passions dominates the novel’s end. I can’t go into too much detail, because it involves one of the book’s major reveals; but suffice to say one word: cats. The sum of all civilization, the hope of future life, the romanticized mystery, magic, possibility—the shimmer of the uncanny, the possibilities of genuine weirdness, the flashes of brilliant speculative physics, the glimpsed-at sense-of-wonder trillennia … it all boils down at the end to, ugh, cats. Ugh! Cats cats cats. Spoilers: cats. I hate cats. Cats, the Nazis of the animal kingdom; cats whose fur and spittle causes life-threatening asthma and other histamine responses in perfectly decent human beings … humans entitled, as is everybody, to life and liberty and the pursuit of happiness. So I was compelled, upon finishing the book, to go: ugh! Cats!