The storyline, people, aliens, societies and technologies that are arrayed before the reader in this novel go far beyond the smart computers, photon torpedoes and planet-splitting weapons-in-the-hands-of-maniacs that tend to characterize the space opera sub-genre to which A Deepness in the Sky belongs. Nevertheless some very evil, maniacal people are to be found in this book.

The action occurs on, and in space above, a planet whose sun regularly, cyclically switches off (literally) after long intervals of providing warmth, life and civilization to its single planet. But because the inhabitants have evolved the ability to hibernate throughout the Darkness, upon Relight civilization emerges damaged but more or less intact. As one such Darkness cycle is about to end two bands of humans arrive above the planet, each having traveled in giant starships at 30 percent the speed of light across light-years of space, cheating time and old age by means of Coldsleep. The first to arrive are starfaring traders who have ambitions to trade with/exploit the planet when it awakens. The second group, representatives of a multi-planetary empire, have similar ambitions but with the emphasis decidedly on the latter process rather than the former.

The tension between these two groups mounts and mounts, as does tension on the surface below where, ignorant of the visitors, different countries are locked in a nightmare war reminiscent, in both technological and psychological terms, of World War I. Each of the combatants had striven, before the atmosphere froze out leaving only cold vacuum, to be last with troops in the field, and equally to be the first to emerge at Relight in order to launch pre-emptive strikes against the enemy.

Contrasting the two human groups, evil is manifest, as might be expected, by a harsh dictatorial political system, but also by sadism, and in particular sexual abuse of women while under a form of mind-control. Authorial use of this devise to show characters' depravity works well in fantasy (for example in Dan Simmons' Carrion Comfort) where protagonists may credibly act to character, that is to say inhumanly. There is never any doubt that the evil protagonists in A Deepness in the Sky are anything but human and consequently this aspect of their characters may be overdone. But either way, countering it all is a fair balance of human fellow feeling, even between non-human and human, and non-human and non-human. Added to this also are plots, counterplots and counter-counterplots, a mix which generates enough twists as to leave aspects of the plot undecided to the very end.

A Deepness in the Sky is a novel of 700-odd pages, and so well instantiated is its universe, so real its characters and events, that I felt, if the author so wished, it could have been sustained for almost the same length again (and that I would have stayed with it).

Vernor Vinge here writes on a big canvas (in fact one similar to that in his A Fire Upon the Deep) and of necessity some of the brush strokes are broad. But this is by no means to say that he has not populated his novel with real people. Thus far I have failed to mention any of them because any such description must include their actions and predicaments, and so would detract from the gradual revelatory narrative form chosen by the author. However, in this context it is worth noting that one of the oft' extolled strengths of the SF genre is that it can give the reader insight into an "alien" mind: what it might be like, not merely to be "someone" else (the preserve of mainstream fiction), but "something" else. At the outset of A Deepness in the Sky, as we first meet the non-human, non-hominid life-form, it appears that Vernor Vinge (writing in standard third-person narrative format) has forgone any attempts at such insights and is playing it straight (with an eye perhaps on the book's film rights). But it is one of the many great surprises of this novel that, as it progresses, this turns out not to be so. The source of the author's apparently effortless ability at insight into and translation of the alien viewpoint is revealed by, no less, the plot of the novel itself!

A Deepness in the Sky is a great long rib-roaring read, with enough subtleties and depth (humankind's first contact with a truly alien species, a consideration of the apparent futility of civilization, an examination of the basic decency inherent in humans and its vulnerability to subversion), to mark it as exceptional, making it a perfect companion for lazy summer days.

Note: Vernor Vinge won the 1999 John W. Campbell Memorial Award (for the best science fiction novel) with A Deepness in the Sky.