Reed takes the premise that, some time in the Earth's distant past, an elder race seeded the Earth's crust with a lattice of degenerate matter, the consequence of which was that somehow this lattice is able to admit passage - via a portal - to an infinite string of alternate Earths.
It's a large-scale production contrasted - as in 'An Exaltation of Larks' with a neatly detailed portrait of small town America.
For a million years, an alternate species of human with large crania and furry faces, have been travelling the Bright - as the chain of portals is called - in both directions from their homeworld, uniting and civilising each Earth.
Jy, the million year old leader of one of the two Founder missions, has now reached our earth.
It's not one of Reed's best, but even here the characterisation is excellent. The people are real; they have flaws. Kyle (an Earth teenager) is a fantasist and is pretending he is one of the aliens' envoys, a Wanderer, in order to impress and seduce women. Confused adolescent males turn up a lot in Reed's work and are generally portrayed with a blunt honesty. With some writers this may have made them seem heartless and cold. However, as with characters in other Reed books, Kyle emerges as a sad victim of himself. Reed makes us see his flaws - perhaps Reed's own early flaws - through more understanding eyes.
Reed is also fascinated by the concept of near-immortal beings who bear comparison with similar characters in the work of Van Vogt who also painted his highly colourful tales against absurdly vast backdrops.
The immortality issue is addressed, but does not satisfactorily convince that the central characters are over a million years old. All wanderers carry a hard memory unit which, if the body is destroyed or wears out, means that the mind of the individual can live on. Rather than explore the ramifications of this technology Reed uses it only as a plot device. However he deals much more effectively with the subject of immortality in later works such as 'Marrow' and 'Sister Alice'
The structure does not help this novel since it is a multi third-person narrative in which we change characters with each section. With three or four characters this device may have worked but six or more gives the narrative a disjointed feel and it lacks coherence.
It is far more complex than it first appears since most of the main characters have secrets, some of which are not revealed until the end, but then again, this is another Reed device which he employs widely elsewhere.