The arrival of a new science fiction novel by someone as well respected and honoured as Greg Bear is always worthy of note. City at the End of Time comes (at least in the uncorrected proof I read) complete with a cover quote from Nobel laureate Doris Lessing, albeit one said about an earlier Bear novel, Blood Music, and its reception, at least in America, has often been favourable. It has appeared on a number of "best of 2008" lists, and I am resigned to it being on the next Hugo ballot.

I say "resigned" because (and this is one of the reasons this review is appearing so late) I personally find it very difficult to bring forward any enthusiasm about this novel. It's not that it's particularly bad—it's just that it's so unremittingly dull, and not just because, at 550 pages, it is another novel that is simply too long. For various reasons, I had to put the book down midway through reading it, and only returned to it some weeks later. When I did, I found that, though I still had a reasonable recall of who these people were and what they were doing, I didn't really care much about them, and did not view picking the book up again as a pleasurable experience.

The basics of the story are as follows: in contemporary Seattle (or is it?), two people, Ginny and Jack, are dreaming of a city in the far future, the Kalpa, where time and the universe are coming to an end. It rapidly becomes clear that the dreamers are swapping consciousnesses with people in the future, who are also dreaming of the past. Ginny and Jack are also "fate-shifters," and carry stones called "sum-runners"; a third fate-shifter is Daniel, who does not dream of the city. Various forces in the present, both benign (or are they?) and sinister (or are they?) are seeking the fate-shifters. Meanwhile, in the future, Jack and Ginny's exchangees, Jebrassy and Tiadba, are heading out into the Chaos to see if there is more left than just the Kalpa. The two periods are linked, as it appears that the end of time is working its way back through the past, threatening destruction upon all of creation and all of eternity. (Interestingly, Bear chooses to depict each time period mainly through the eyes of the people belonging to it—we learn very little, for instance, of what Jack thinks of Kalpa or what Jebrassy thinks of Seattle, and the times spent in each other's bodies tend to be reported to the reader rather than experienced.)

At a recent British Science Fiction Association meeting, John Clute commented that City at the End of Time is an example of a novel in dialogue with past works of SF. He has singled out The Night Land (1912) by William Hope Hodgson as one such work, and the parallels are obvious. Both novels involve dreaming of the future, and a city that is barely holding out against the forces of chaos that surround it. But there are many other resonances with past SF works in Bear's novel. The notion of dreamers swapping personalities through time can be found in H. P. Lovecraft's "The Shadow Out of Time" (1936, and itself influenced by The Night Land, which Lovecraft admired), and a similar idea features in Iain Banks's Walking on Glass (1985). Kalpa reminded me of the end of time as depicted by Neil Gaiman in The Books of Magic (1989), whilst echoes can be seen of the eschatology of Michael Moorcock's Dancers at the End of Time (1981), or the works of Stephen Baxter or Olaf Stapledon, in whose Last and First Men (1930) people from the end of humanity mentally contact people of the time of writing. Some of the groups seen in the contemporary sections, including what is close to being a coven of witches, remind me of those forces maneuvering in the final season of Buffy the Vampire Slayer.

The trouble is, all of this is not put together terribly well. As in Jon Courtenay Grimwood's End of the World Blues (2006, and in my view a better novel than City at the End of Time, though far from Grimwood on top form), the present and future sections do not mesh terribly well. This is partly to do with there being too many ideas in the book. A decent novel could have been got out of either the idea of fate-shifting or of dreaming of the future; but by putting them both in, Bear overcomplicates his storyline.

But most important is the fact that I found it very difficult to make sense of what was going on. This isn't necessarily a bad thing. I have little idea how the alternate timelines in Christopher Priest's The Separation fit together, but that doesn't stop me enjoying the novel. But Priest gives the impression that he at least knows how it all works, even if he's not telling the reader. In City at the End of Time, Bear just seems to be moving the goalposts as it suits his narrative. I suspect that even if I did read the whole novel again, informed by the "revelations" at the end, I still wouldn't be able to work out what was going on.

Take, for instance, the fate-shifters. The back cover blurb on the proof explains them as being "born with the ability to skip like stones across the surface of the fifth dimension, inhabiting alternate versions of themselves." That does seem to be what Daniel does. But Jack only sometimes does this—at other times he appears to shift probability around him. And the people pursuing him seem to be able to catch up with him, even when he shifts across alternate universes. Does the action shift across alternate timelines? Do the timelines absorb each other? Is this to do with the destruction of alternate timelines by the chaos at the end of time? None of this is ever clear, and indeed it's never clear that Bear knows. The same goalpost-moving goes on with the dream-shifting, where sometimes the dreamer ends up as an extra consciousness inside the head of their equivalent in the other time, a bit like Lily Tomlin's character in All of Me. For what is ostensibly an SF novel rather than a fantasy, this lack of consistency is quite a surprise.

And then there's the end—and here I must inevitably include spoilers. It turns out that the Chaos at the end of time is in fact a sentient entity called the Typhon, which wants to be free of its own existence, and can only become so through destroying all eternity. As all times and universes collapse into one another, the Typhon is confronted ... and destroyed by an infinite clowder of cats, which throw themselves at it like Red Army punishment battalions at German lines. Cats have been appearing earlier in the novel, but their significance for its dénouement comes somewhat out of the blue. Meanwhile, all the other characters unite to allow Jack and Ginny to save the universe. Or just save one universe. Or possibly not save the universe at all, but assist in the birth of a new universe out of the death of the old. Again, it's not easy to tell, and by this point, it was for me hard to care. I just wanted the novel to be over.

As I write this, I am beginning to wonder if City at the End of Time is in fact Bear rewriting the superhero comic "event" miniseries Crisis on Infinite Earths, in which DC Comics reduced all their various alternate universes down to one, as an SF novel, perhaps with a bit of the origin story of Marvel's Galactus, only survivor from the old universe to pass through into the new, thrown in. Certainly, there are similarities, such as the way all universes seemingly need to be brought together to ensure that anything can survive at all. But the sort of hand-waving to overlook inconsistencies that an author can get away with in a superhero comic is much harder to get away with in an SF novel.

Tony Keen reviews for Vector as well as Strange Horizons. But he's been quite tardy lately.