C.S. Friedman's This Alien Shore can be summed up in two phrases: terrific world-building, substandard plot. While I enjoyed it, I cannot recommend it unless plot is not one's make-or-break concern in a novel.
This Alien Shore explores questions of humanity via the central premise of its universe: the mutation of Earth's first faster-than-light travelers into numerous Variations, which appear to differ for each trip. When news of the effects reached Earth, it cut all contact with its colonies. Some time later, one of those colonies has re-established space travel with a different, non-mutating drive, but under the exclusive control of a secretive Guild. The book opens with two different threats to the Guild's control: one, a teenaged girl named Jamisia, is on the run without knowing why; the other, a computer virus, is interfering with the programming of Guild outpilots—with potentially lethal results.
Unfortunately, these two plot strands never really connect in any meaningful way: the people involved do, but the topic of the outpilots is all that links the actual events. However, the pace is generally fast, which helps cushion the fact that most of the major plot points were no real surprise to me. (One—the source of the virus—I didn't guess ahead of time, but that was because I didn't try; there were too many options.)
I did find the universe described in the book engrossing enough that the plot problems only really bothered me after I put the book down. The Variations allow the book to have as many different kinds of beings as, for instance, James White's Sector General series; as in those books, the implications of these physical and mental differences are often fascinating. Particularly interesting are the Guerans, from whom come the Guild of outpilots. Their Variation is actually an infinite number of Variations: it affects the brain only, resulting in what appears to be the entire spectrum of mental patterns, processes, and what the novel's Terrans term defects. On top of this is layered one's kaja, which roughly corresponds to a basic personality type or category of Variations. For instance, one of the main characters is an iru computer security expert, Dr. Masada; at one point, he muses about his dead wife:
Had he loved her? Gueran science wasn't sure if an iru could love. The chemicals were there for it. Sometimes they even combined properly. Wellseekers  couldn't tell the difference.
But subjective experience? No one was certain. No iru understood the language of love well enough to confirm or deny it.
He missed her terribly.
 internal monitors and regulators of one's physical state
An array of such interesting characters grace the book, though this reader, at least, would have been happy to see more time spent with some of the more intriguing and unusual ones. The physical elements of the universe are interesting as well, though less detailed than the human ones. Unfortunately, though it is certainly worth reading for the world-building, the plot ultimately prevents This Alien Shore from being a fully satisfying work.
%T This Alien Shore %A Friedman, C.S. %C New York %I DAW %D 1998 %G 0-88677-799-2 %P 564pp %O paperback
Copyright July 4, 2000 by Kate Nepveu. Originally posted to rec.arts.sf.written