Thousands of years hence many races inhabit a universe where a mind's potential is determined by its location in space
- from superintelligent entities in the Transcend to the limited minds of the Unthinking Depths where only simple creatures & technology can function Nobody knows what strange force partitioned space into these 'zones of thought' but when the warring Straumli realm use an ancient Transcendent artefact as a weapon they unwittingly unleash an awesome power that destroys thousands of worlds & enslaves all natural & artificial intelligence Fleeing the threat a family of scientists including two children are taken captive by the Tines
- an alien race with a harsh medieval culture
- & used as pawns in a ruthless power struggle A rescue party not entirely composed of humans must free the children
- & retrieve a secret that may save the rest of interstellar civilization