Diaspora

Close up, they could see through the partially reflective surface into the dazzling world below. Broad helical carnivorous weeds shone in gold and turquoise; one swarm of mites avoiding their poisoned fronds were a deep, rich red, another were (pre-Lacerta Earth) sky blue. All Swift life made heavy use of sulfur chemistry; carbon dominated, but some primordial accident seemed to have pushed sulfur into sharing the structural role, and the intensity of the colors was one side effect.

"Maybe all of this was engineered from scratch," Yatima mused. "For decorative purposes. Maybe Swift was sterile and airless, and someone came along and built this ecosystem, molecule by molecule. Using heavy isotopes to make it last a little longer. Like sculpting in gold, to avoid corrosion."

"No. Wherever the Transmuters are now, this must have been their native biosphere." Orlando seemed grimly convinced, as if the alternative was too decadent and frivolous to contemplate. "They would have substituted the isotopes slowly, feeding them into the existing atmosphere over millennia. It was a mark of respect that they didn't wrap their home in a protective sphere, or shift its orbit, or modify its sun. They slipped in a change at the lowest possible level, underneath the biochemistry."

Yatima guided vis car over the puddle. Vivid green eels several millimeters long undulated by, much faster than the probe. A red-and-yellow twelve-legged spider walked upside-down on the membrane, picking out the flatslugs that lived embedded in it. Yatima didn't have much sympathy for the prey; they blithely fed on the protective polymers that almost every other species took the trouble to synthesize and excrete. Then again, it was a niche begging to be filled, and none of these creatures did anything with a conscious purpose.

"If they cared so much about their biological cousins, they can't have been expecting Lacerta. There's no sign of any built-in protection against a gamma ray burst."

Orlando was unswayed. "Maybe the only thing they could have done that would have made a difference were anathema to them. And they must have known that even if there were massive extinctions, they'd given the biosphere enough general resilience to recover."

They'd found few fossils on Swift, so it was difficult to judge the extent to which life had been disrupted by the burst. Models showed that most of the existing species would have coped relatively well, but that was hardly surprising; they were the ones that had survived, not a representative sample of pre-Lacerta life. The heritable material here cycled between five different molecular coding schemes in successive generations; some species used a "pure" scheme, all Alpha leading to all Beta, Gamma, Delta, and Epsilon, while others had mixtures o all five in every generation. Some biologists claimed to have identified a genetic bottleneck due to Lacerta, but Yatima wasn't convinced that anyone understood Swift's biochemistry well enough yet to say what a normal level of diversity would have been.

"So where are they now? Have they been swallowed by an Introdus, or scattered by a Diaspora? If you can read their minds about everything else, that ought to be an easy question to answer."

Orlando replied with sublime confidence, "Would I be here, if I thought I was wasting my time?" His tone was ironic, but Yatima didn't believe he was entirely joking.

They'd scoured the planet from orbit, looking for cities, for ruins, for mass anomalies, for buried structures. But a civilization as advanced as the Transmuters could have miniaturized their polises beyond any chance of detection. One faint hope was that since they'd bothered to intervene in the fate of Swift's organic life, they might show themselves at the oases now and then. Yatima wasn't optimistic. If they were still on the planet they could hardly be unaware of their visitors, but they hadn't chosen to make contact. And if they didn't want to be seen, they were unlikely to send big, clumsy, millimeter-wide drones plowing through these puddles. Yatima watched a rare translucent creature swim by beneath the probe, propelled by a jet of water it created by contracting its whole hollow body. Ve'd thought ve'd be prepared to study a world like this, patiently helping the biologists extract the kind of insights into evolutionary principles offered by even the most modest extraterrestrial biosphere. There were no spectacular new body plans or life cycles here, no strategies for feeding or reproduction that hadn't been tried out back on Earth, but at a molecular level everything worked differently, and there was a vast labyrinth of utterly novel biochemical pathways to be mapped. Yet the Transmuters made it almost impossible to care. Their absence—or their perfect camouflage—monopolized everyone's attention, transforming the intricate machinery of the biosphere into a very long footnote to a far more mesmerizing blank page.