Tor, 1998, 352 pages
Only children can colonize the planet Prokaryon, genetically modified for a world whose chemistry kills unaltered adults. A colony of orphans struggles to survive, and finds the planet hides strange secrets.
The Prokaryan landscape is ordered, as if by unseen gardeners, hidden "masters" no human has ever found. The weather behaves as though designed to meet the planet's needs. When fire threatens a forest, a rainstorm appears, only to dissipate when the fire is put out.
When a ruthless corporation threatens to terraform Prokaryon, to recreate it for "normal" humans, there is a sudden urgency to find the intelligent life form directing the planet. For only then can the colonists save their world—and reveal unexpected possibilities for the human future.
Usually "hard SF" refers to physics and engineering — crunchy orbital mechanics and interplanetary travel with terms like "delta-v," weapons and other technology that at least has some plausible physics behind it. The most esteemed SF novels are those written by actual scientists and engineers (or those who could fake it well enough, like Heinlein, who had his starship pilots working out interstellar routes with slide rules...) Larry Niven's Ringworld is a classic because while a ring around a star is probably not something that an advanced alien race could actually build (or would want to, if they could), he at least made it appear achievable, with the proverbial "sufficiently advanced technology." (And then he wrote The Ringworld Engineers when his fans corrected his math.)
Odd, then, how rarely we pay the same amount of attention to biology. Trekkies want to know all the technical details of warp drives and phasers, but are content to accept a universe full of humanoid aliens with various shades of wrinkly foreheads.
(Yes, yes, I know there is some semi-official canon out there about a "forerunner" race that seeded the Star Trek galaxy with the ancestors of humans, Klingons, and Vulcans, et al, but explain to me how Vulcan biochemistry is so frikkin' alien they have green blood and yet they can interbreed with humans?)
The Children Star takes the opposite path — interstellar travel is simply handwaved away as a thing that exists, as are moon-sized spaceships and "white holes" to sterilize planets, but Joan Slonczeswki's biology is at least as rigorous as Heinlein's rocket science or Niven's planetary engineering. Not surprisingly, Joan Slonczeswki is in fact a professor of microbiology.
The planet Prokaryon has an alien — really alien — environment. All life there has triplex DNA and is made of amino acids that just don't play well with terrestrial life, and yet it has a complicated, evolved ecology populated by zoöids and phycoöids and microzoöids, all completely incompatible with the humans who settle on it. So humans have resorted to "lifeshaping," which is the slow process of bioengineering humans to adapt to the Prokaryon environment, able to eat Prokaryon flora and fauna and breathe Prokaryon air. Usually this only works when begun with children, which is how the Spirit Callers, a monastic order, wound up with a small settlement on Prokaryon, taking care of lifeshaped orphans abandoned on other worlds.
There is an interstellar government called the Fold, made up of several planets of human descent, each of which has its own biological and psychological quirks and political factions. The story alternates between survival and mystery on Prokaryon, where there have long been traces of a hidden intelligent race, but no hard evidence, and interstellar political machinations, where one of the wealthiest and most powerful men in the Fold wants to just boil Prokaryon's surface and terraform it.
The mystery behind the alleged "hidden masters" of Prokaryon maintains the suspense for about the first two-thirds of the book, along with the question of whether or not the Spirit Callers and their allies, including simian scientists and free sentient machines, can save the planet.
In many respects, The Children Star is a traditional space opera, with an Asimovian planetary mystery. But the hard bio-science and the thoughtfully worked-out factions and societies of the Fold elevate this book above most of its kind.
The Children Star is the third book in Slonczeswki's Elysium Cycle, but it takes place thousands of years after the preceding one, so it stands alone well enough. I was surprised by how much I liked this, and consider it one of the best SF novels I have read in the past few years.
Tor, 200, 384 pages
Brain Plague is the sequel to The Children Star. Spoilers for the previous book below.
In The Children Star, we discovered the world of Prokaryon, which is inhabited by a race of sentient microscopic organisms. These organisms can inhabit ("infect") larger life forms — including humans. So the first book was about the discovery of the micros and how to deal with them. This is the Big Idea in these books, and it's really a fascinating one; each race of microorganisms in any given host, living at a dramatically accelerated timescale, becomes its own independent civilization, evolving very differently from the same ancestors in another host.
Brain Plague takes place years after The Children Star. "Micros" from Prokaryon have spread to other worlds in the Fold, and are now cultivated by select hosts who live in a symbiotic relationship with their micros. People with micros benefit by having an entire intelligent civilization living in their bloodstream. Since micros live much faster than humans, generations live and die in the span of a year. The protagonist of Brain Plague is a starving artist named Chrysoberl who has come from a poor planet to the "big city" of one of Elysium's cosmopolitan worlds. Chrysoberl is selected for an experimental medical treatment, which turns out to be a batch of micros, who transform her art and make her an important artist and architect who is suddenly launched into the Fold's high society.
The most interesting part of Brain Plague is the relationship between human hosts and their micros, who worship their hosts as gods. Except for the ones who go rogue and instead take over their host bodies. These become known as "vampires," and as the title of the book suggests, there is a lot of intrigue surrounding who's been infected by vampire micros. The class and cultural divisions of the Fold are as interesting as most space operas. There aren't really any aliens (aside from the micros), but this is a far future, post-human world, so besides baseline humans, there are Sentients (AIs with artificial bodies), Sims (evolved ape-like sentients), and Elysians, also known as "Elfs" - evolved, nearly immortal post-humans.
The economic and cultural intrigue provided an interesting plot, and the biochem SF was the main attraction of this book, but I found it considerably less engaging than its predecessor. There was not much mystery about the aliens, as this was not a first contact story, and the latter half of the book became rather mushy with Chrysoberyl's romance with a hunky authority figure who of course gets infected with vampire micros.
A decent SF romp with creative ideas outside the typical space opera, but start with The Children Star.
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