Over the holiday I read some hard SF, since I wasn't doing any hard drinking. I read its accompanying volume, A Fire Upon the Deep, while I was subletting a cat-hair-covered studio apartment in Brooklyn a few years ago and enjoyed it. Deepness is set in the same universe, but although one's appreciation of the book is enhanced by the melancholy knowledge of the characters' circumstances and eventual fates, it can stand alone.
Essentially, two cultural expeditions competing for access to one of the only non-human sentient civilizations (the Spiders, a race of chitinous but somehow endearing giant bugs) fight each other to a draw and are forced to lurk at the edge of Spider space until that civilization develops to the point where it can be usefully exploited and they can use its resources to leave the system. The competing expeditions are the Qeng Ho, uber-capitalist itinerants, and the Emergents, who come from a totalitarian world that has taken slavery to new and powerful levels.
The book is almost relentlessly downbeat, and at one point becomes almost an exercise in metafiction; the lurking humans have been closely monitoring the Spider world and have grown emotionally attached to certain individuals through station-wide broadcasts of translated Spider programming. When it looks like things may go badly for their favorite Spiders, the crew petitions that something be done to ensure their safety. While this is going on, of course, Vinge has made clear that things may go very badly for both the Spiders and our intrepid human heroes, and the reader herself may have the urge to petition the author not to annihilate those she has grown to hold dear.
I won't spoil the ending (mostly because it's one of the few parts of this very long book that seems hurriedly explained), but I did find it hard to put down. Recommended.