Vernor Vinge's A Fire Upon the Deep (1992), to which The Children of the Sky is a direct sequel, was an almost-ultimate space opera involving multiple Singularities and an ingenious first contact story, which explored ideas of identity in mind-expanding ways and contained two great science fiction ideas. The first was the galactic zones of intelligence and superintelligence which stretched from mundane levels to transcendent "Powers," one of which becomes known as the "Blight" when it is awoken/stimulated by human researchers, and threatens to devastate the known universe. Attempting to escape this Blight and the humans it has taken over, a sleeper ship carrying a defensive device lands on an unknown planet which is the home of Vinge's second great idea; the Tines, dog-like aliens who share one consciousness among multiple (four to eight) bodies. Culturally in a late mediaeval phase, their rival factions are quickly inspired by these strange new aliens. While the adults from the sleeper ship are quickly killed, two children, Johanna and Jeffri, survive, and are taken by different factions among the Tines. Following the sleeper ship is the Out of Band II, a ship crewed by the archivist Ravna Bergsndot, another human called Pham (seemingly a construct devised by a benign Power) and two skroderiders, plant-like aliens, named Blueshell and Greenstalk. After much political complication, Ravna and Pham trigger the Blight countermeasure, which results in Pham's death, and the surrounding space is shifted into the Slow Zone, removing the immediate threat from of the Blight. However, a fleet consisting of Blight-controlled humans (or "Blighters") is on its way.

The Children of the Sky, which takes place on the Tines' world some years after the events of the first novel, has a closer focus and a more limited setting. The children in coldsleep aboard the OoB II (or “Oobie”) have been revived, and Humans and Tines are now living in uneasy alliance. The Blighter fleet is still on its way, but boundaries between Zones are becoming unstable and Ravna is increasingly aware that the combined Human-Tinish technologies must be advanced to a high enough level to combat the invasion. However, most of the children have quite literally slept through the events of the previous book and have no emotional contact connection with them. The Disaster Study Group, a faction among the children led by Nevil Storhert, concludes that Ravna is obsessed with a danger that may not actually exist: that the Blighter Fleet may even be a rescue mission. Jefri, in the previous novel a young child and now a rather rebellious teenager, flirts with the group's ideas and estranges himself from his sister and from Ravna. Meanwhile, the rivalry between Tine factions is increasing. The tine-pack Woodcarver, who won the war against Flenser and Steel in the previous novel, is now threatened by the rivalry of Tycoon, who has become the world's greatest trader through exploiting the resources of its tropical zone; the focus of much of the book's action and interest.

Children is a vast tapestry of political manipulation, but does it deliver the same scope, and the same bangs, as its predecessor? The book seems to concentrate on minutiae. Divorced from their context of a network of multi-species civilizations, the human characters seem curiously less representative of an advanced civilization of their own and more like ordinary Americans who encounter packs of talking dogs. Cutesy coinages like "Blighter" and "Oobie" don't help to alleviate this impression.

The children, coming into this strange new world as children, are divorced from their own cultural background (though they have significant access to its history via databases and Ravna, an adult from a different environment), but the tensions which lead to the Disaster Study Group and the emotional and political wrangling in the background remain, largely, as sidebar discussions, told rather than shown. Yes, in a novel like this, we need a hook into concepts that we could understand, but even the most effective of his human characters, such as Ravna and Johanna, seem rather one-dimensional. Nevil, the human villain, is much less memorable and fully drawn than are the Tines Tycoon or his sidekick Vendacious, who have clearer if much more complex motives for what they do.

Vinge is much better with his aliens, but Children’s "big Tinish idea"—showing us more of the Tropical Choir, the mob-like inhabitants of the tropical regions where the extreme density of population pressure breaks down the discrete pack structure—doesn't quite work because the nature of such mob-consciousness is only hinted at. Parts of the novel involving masses of tropical singletons crossing over to the civilized "Domain" read interestingly like first world immigration anxieties, but, unlike the exchange of panicky and sometimes incomprehensible messages between interest groups in the first novel, which functioned as a wry satire of contemporary internet to- and fro-ing and was one its highlights, these are either not intended to be satirical, or not well executed.

Once we slow down and read the book carefully, however, it's possible to color in some of the broad outlines. The Tropical Choir is at first seen as an ecstatic but virtually mindless state, in the sense that human and even pack singularity is an individual "mind." However, once communication is established between "civilized" Tine society and the Tropical Choir, through what seem to be temporary packs known as "godsgifts," it is clear that the Choir is capable of significantly more complex organization than is initially believed: "the Choir as a whole may not have what you call intelligence," says a version of godsgift at one point, "but it is a happier way to know reality than is your stunted existence" (p. 324). Although locked in a "slow" Zone, and on a level broadly equal to humans, the Tines seem to have the potential for a much more sublime transcendence.

For much of the book, too, the relationship between between Jefri and his Tine-pack friend Amdi, who have gone through (and go through again) some pretty traumatic experiences, becomes even more "a boy and his dog"-like than it was in Children's predecessor, where both characters' youth might have excused it. However, about two thirds into the novel, things change. Amdi, Jefri, and Ravna are traveling through hostile territory, and Amdi suddenly comes to the fore as a smart and funny (as opposed to cute) character. It is his idea to pass the group off as a traveling entertainment troupe. This is perhaps hardly an original idea, but it is one which Vinge carries off very well and which leads to some deeper exploration of the characters. We see an intriguing, even moving, aspect of Tine psychology as the singleton Ritl, a semi-sentient fragment of a former pack whose clownish antics are part of the "circus," starts "bothering the parts of me [Amdi] . . . the parts who like her" (p. 288). Amdi's grit and intelligence are part of the eventual resolution of the tangled web of events. If the true moment of estrangement in much science fiction is the realization that the alien is not human, the parts that give The Children of the Sky its life and interest arrive when we forget that the Tines are not, despite the frequency of petting, "best friend" relationships, and physical resemblances to canines, dogs. They are people, and sometimes not very nice people at that. They have their own agendas.

We realize too, as the novel goes on, that the technology which is (we hope) to defeat the oncoming fleet will be a fusion of the knowledge to be retrieved from human databanks and the know-how of the Tine packs. Hints of how this is to happen lie in the way the human technology of radio is adapted by the Tines, as a way of enabling pack consciousness/communication to be extended over a greater physical area than would otherwise be possible. Neither bio- nor social engineering but partaking of both, the way Tine leaders' creation of new entities through their own version of a eugenics program is fascinating and at times chilling.

The problem is that this is not a novel where all is resolved in the end. At the end of Children the Blighter fleet has yet to arrive. This is as much a story of the human characters rediscovering their parts in a much wider story as it is of the civilization and ecology of the Tines' world, and by the novel's close we are still a long way from that story's end.

Yet somehow, the novel works. The explorations of Tinish culture and psychology, which highlights differences from our notions of individual and cultural reproduction, are complex and require careful reading, if only because it forces us to re-examine our idea of what constitutes a character when a "person" can be added to or subtracted from to become someone very different). They are also masterly examples of SF's fascination with the alien. The Tines, of course, are baffled at times by the idea that intelligent consciousness can exist in single bodies. The cultures led by Woodcarver, Tycoon, etc. come up against aspects of their own species-nature which they do not fully understand, and our own reading of this through the Tinish encounter offers us a particularly acute sense of estrangement. We—as "human" readers—constantly have to bear in mind that we are understanding this alien encounter through the minds of other aliens rather than an easily grasped "default" norm. Vinge perhaps takes us the long way round, but we are back to A Fire Upon the Deep's mosaic of different intelligences and mindsets.

While we still have to wait for the final showdown, some of the human characters now have a sense that things are more precarious than they seem, and others are working closely if not altogether hand in glove with the Tines to kickstart technological and political progress. There is a strong sense of change going on, and once we change our focus from plot to idea, and look underneath some of the apparent cosiness, that sense of change becomes inspired. This is an interesting world, and while we wait impatiently for the melodrama to unfold fully, we feel that the world is growing and the climax, when it comes, may yet achieve the grandeur of the first novel.

Andy Sawyer is librarian of the Science Fiction Foundation Collection at the University of Liverpool Library, Course Director of the MA in Science Fiction Studies offered by the School of English, and a widely published critic. He is Reviews Editor of Foundation: The International Review of Science Fiction. He recently co-edited (with David Ketterer) Plan for Chaos, a previously unpublished novel by John Wyndham. He is the 2008 recipient of the Clareson Award for services to science fiction.