The galaxy (each galaxy?) is divided into “Zones of Thought,” each with differing underlying physics. In the Slow Zone, faster-than-light travel (FTL) is impossible. Outward in the Beyond, FTL is a possibility; also it is possible for more advanced forms of sentience, like true artificial intelligence, to function. Outward still, the Transcend is the realm of the Powers, god-like AI’s (basically) that are generally occupied with activities that those of us in the lower Zones could never even understand. Why the Zones exist (are they tied to gravity – more matter towards the center of the galaxy?) and why thought capability is affected along with FTL travel, is a mystery that is explained in the end of the novel….
There are thousands of civilizations in the galaxy. In the Slow Zone (no FTL), there’s barely enough time before extinction for a civilization to travel far enough to make its presence known to the galaxy at large. In the Beyond though, everyone’s connected to the “Net of a Million Lies” which functions kind of like Usenet (or blogs) – authors make posts and assign it certain keyword topics so interested parties can follow along. I thought this was a cool way to tell parts of the story – we see events unfold in some chapters as a series of posts from different authors; you get the sequence of events but also the different perspectives and motives of various groups. Some of the posts are very humorous, too.
An ancient rogue Power, nicknamed “the Blight,” has been awakened by a human civilization. It is much more powerful, capable of vast destruction (even killing off other Powers), and interested in conquest of Beyond civilizations than other Powers heretofore. It’s kind of like a smart computer virus, traveling through the “network” of space. Whatever system (be it a solar system or civilization or other AI) it touches becomes a part of the Blight, under its total control. To make matters worse, humans get the blame for this creation and are therefore in danger from other civilizations as well as the Blight itself.
The one hope seems to be a refugee ship, crash landed on a world deep in the Low Beyond, launched shortly after the Blight’s creation. One of the protagonists, a human named Pham Nuwen, is the recipient (victim?) of “godshatter” – in a nutshell, he’s had a dying Power (murdered by the Blight) download programs into him, although what they are is kind of unclear. Pham knows what needs to be done, but not necessarily why. Anyway, he has reason to believe the refugee ship has a Countermeasure on board, capable of defeating the Blight.
The world the refugee ship lands on is inhabited by a medieval civilization of “Tines,” dog-like creatures that function in packs of between four-eight members. Each pack is an individual; the members communicate telepathically and function as one. A good portion of the novel is two rival Tines groups using the ship and survivors (a brother and sister) as pawns in their struggles against each other. The whole pack-mind concept in the novel is unique, well executed and presents a lot of interesting things to think about.
<spoiler>Once Pham gets to the ship, he activates the onboard Countermeasure — speculated as a creation of the Power(s) beyond the Powers. The Countermeasure is as ancient as the Blight itself — both have been awakened and then put in statis at least once before millions of years ago, maybe even longer. The Countermeasure changes the boundaries of the Zones of Thought (or maybe even created the Zones in the first place). In this case, the only way to stop the Blight is to trap it in a Zone where it can’t travel FTL and can’t function at a high level (or at all, probably, since it is an AI). In the end, the Countermeasure pushes out the Slow Zone all the way to the edge of the Beyond (at least), trapping the Blight. Presumably the Zones will slowly recede over the next few million years until the Blight is again near the Transcend and capable of waking…. Sad side effect of trapping the Blight is that the Net civilizations are effectively cut off from each other, permanently.</spoiler>
Very fun and interesting story. As you can tell, there is a theme of networks throughout the book — the Net, the pack minds, the AI Blight “network”. Vernor Vinge is a Computer Science professor and the novel was written in the early 90’s; one has to speculate that he was inspired by the beginnings of the Internet.