Faster-than-light travel remains impossible near Earth, deep in the galaxy's Slow Zone--but physical laws relax in the surrounding Beyond. Outside that again is the Transcend, full of unpredictable, godlike "Powers". When human meddling wakes an old Power, the Blight, this spreads like a wildfire mind virus that turns whole civilisations into its unthinking tools. And the half-mythical Countermeasure, if it exists, is lost with two human children on primitive Tines World.

Serious complications follow. One paranoid alien alliance blames humanity for the Blight and launches a genocidal strike. Pham Nuwen, the man who knows about Countermeasure, escapes this ruin in the spacecraft Out of Band--heading for more violence and treachery, with 500 warships soon in hot pursuit. On his destination world, the fascinating Tines are intelligent only in combination: named "individuals" are small packs of the dog-like aliens. Primitive doesn't mean stupid, and opposed Tine leaders wheedle the young castaways for information about guns and radios. Low-tech war looms, with elaborately nested betrayals and schemes to seize Out of Band if it ever arrives. The tension becomes extreme... while half the Beyond debates the issues on galactic Usenet.

Vinge's climax is suitably mind-boggling. This epic combines the flash and dazzle of old-style space opera with modern, polished thoughtfulness. Pham Nuwen also appears in the nifty prequel set 30,000 years earlier, A Deepness in the Sky. Both recommended. --David Langford