Dark Ararat (29 page)

“They could have been planted,” he said to Solari, although he knew exactly how desperate the suggestion was. “Given that we all wear heavy-duty smartsuits, you can’t have much in the way of forensic evidence. Maybe this whole setup is fake—rotten through and through. Maybe the bubble’s logs have been altered too.”

“So who
did
fake it all?” Solari countered, plainly exasperated. “Why? Which of the seven had the motive, the time, the skill to do the murder
and
the cover-up? Come on, Matt. We have to do better than
that
.”

“I don’t know,” Matthew said, helplessly, knowing that if he had to stay ahead of the game he had to improvise something much better. “What I want to think is that Bernal really did
find
the artifacts, that they really are evidence of the continued existence of the indigenes … but that someone didn’t want him to reveal that fact. Maybe the artifacts
are
real. That’s another thing neither of us is competent to judge.”

“Unfortunately,” Solari observed, drily, “it’s difficult to think of anyone who is. But it still won’t wash. If they really were made by aliens, Delgado would have shouted the news from the rooftops the moment it broke. Nobody could have imagined, even for a moment, that they could keep it quiet—and if they had they certainly wouldn’t have used one of the alien artifacts to commit the murder while they had a perfectly good stainless steel knife in their belt, would they?”

Matthew had to concede that it was all true. He was thoroughly ashamed of himself. He had always thought of himself as an unusually accomplished improviser, especially under pressure. He knew that he ought to be able to make up a better story, even if he couldn’t actually intuit the truth. He was recently arrived on an alien world, exhausted and ill-fed, but none of those circumstances constituted an acceptable excuse.

“I’ll work it out,” he told Solari, grimly. “I promise you that. I’ll work it
all
out. Every last piece of every last puzzle. I’m Bernal’s replacement as well as his friend. It’s up to me to carry through his plan, whatever it was, and that’s what I intend to do. You can spread that around if you like, on the off chance that it will make the murderer take a pop at me. But either way, I’m going to sort this mess out.
Properly
.”

Solari finally cracked a smile. “That’s what I wanted, Matt,” he said, softly. “Just be sure you let me in on it first, okay?”

TWENTY-THREE

W
hen Matthew and Solari returned to the bubble Solari decided that the time had come to interview Maryanne Hyder about Delgado’s murder. Matthew decided, for his part, that it was time to confront Tang Dinh Quan.

The biochemist was in his laboratory, patiently monitoring the results on an electrophoretic analysis. The robot-seeded slides were so small that he had to use a light microscope to read the results. The shelves to either side of him were full of jars containing preserved specimens of tissues and whole organisms—mostly worms of various kinds—but pride of place on his largest work-surface was given to the massive biocontainment cell into which he had decanted the tentacled slug that Blackstone had brought in that morning. The interior of the cell was fitted with robot hands that Tang could use to manipulate the specimen, administer injections, and take tissue samples, but the slug seemed perfectly serene and relaxed. It was easy to imagine that its tiny eyespots were focused on its tormentor, while its distributed nervous system contemplated revenge for all the indignities he might care to heap up on it.

Matthew knew that Tang was one of numerous surface-based scientists working on the proteomics that would eventually supplement the genomic analyses carried out by Andrei Lityansky’s counterparts at Bases One and Two. Proteomic analyses had never acquired the same glamor as the genomic analyses upon which they were usually considered to be parasitic, but biochemists tended to regard theirs as the real work. Hunting and sequencing exons was a fully automated procedure, while the patient work of figuring out exactly what the proteins the exons produced actually
did
, in the context of a functioning physiology, required a talent for collation and cross-correlation that even the cleverest AIs had not yet mastered.

Forearmed by Lityansky, Matthew already knew that the proteomics of the complex organisms of the Tyrian ecosphere was likely to be just as convoluted as the proteomics of Earth’s “higher” organisms. On both worlds the genomes of the most sophisticated organisms had accumulated many idiosyncrasies as the improvisations of natural selection had built more potential into them. But Ararat-Tyre had an extra complication: the supplementary genome that might or might not be an independent homeobox.

“Is there anything new that I need to know about?” Matthew asked, figuring that it would be better to begin on a thoroughly professional basis.

Mercifully, Tang wasn’t the kind of man to quibble about the meaning of
need
. He was ready to share his discoveries with all apparent frankness.

“My colleagues at Base One are beginning to make progress with their analyses of the cellular metabolism of a wide range of plants and animals,” he said. “As you’d expect from the fundamentals, many of the functional proteins made by the nucleic acid analogue are very similar to those made by DNA. The functions of the second coding-molecule are much more arcane. There are no earthly analogues for the relatively few molecules we’ve so far identified as products of that system, all of which are protein-lipid hybrids. Until we can establish an artificial production system it will be difficult to test the hypothesis that its functions are mainly homeotic, but we have found that high concentrations of key hybrid compounds are associated with growth.
This
specimen may be very useful to us in that respect; now that I know what to look for I may be able to confirm that its exceptional size is correlated with unusual activity of the second replicator. If I can prove that the slugs can alter their size in response to environmental circumstance, and that growth isn’t an ongoing, unidirectional process, it will be the first step in establishing a key difference between Tyrian and Earthly organisms. Proving that they’re emortal will be harder, and testing the limits of their metamorphic potential harder still, but it
is
a start. We know now that the apparent similarities between Tyrian animals and their Earthly analogues conceals radical differences, and that the entire ecosphere is far more alien than it seemed at first.”

“Have you been able to do much work on the higher animals?” Matthew asked. “Lityansky didn’t seem to have looked at anything as complicated as the slug, let alone the mammal-analogues.”

“When I first came here,” Tang said, “I was excited by the possibility that we might be able to go straight to the top, as it were, by recovering some genetic material from the city-builders, but the quest has so far proved frustrating. We know that there are monkey-analogues further downstream, which are presumably the nearest relatives of the humanoids so far observed, but our attempts to trap mammal-analogues in and around the ruins have been just as frustrating as our attempts to discover humanoid remains. The river expedition was, of course, intended to compensate for those disappointments. I assume that it still is. One of my fallback projects—fortunately, as it has turned out—was to investigate the class of creatures that includes the one that incapacitated poor Maryanne. My initial interest had nothing do do with the fact that all the species in the group are poisonous, but the work Maryanne and I have done on the toxins has proved very useful. You’ve presumably been informed that the genomics of organisms like this one seem unusually complex even if one sets aside the matter of the second coding molecule. The genomic potential of the DNA-analogue seems to be far more elaborate than its representation in quotidian proteomics.”

Matthew had little difficulty in cutting through Tang’s excessively pedantic choice of terminology, which inevitably tempted him to an opposite extreme. “You mean that it has more genes than it seems to be using at any one time,” Matthew chipped in. “In other words, the orthodox exon-bank has all kinds of tricks up its sleeve—just the sort of thing that a serial chimera would need.”

Tang didn’t take offence at the crudity of Matthew’s presentation. Indeed, he recognized its propriety with a smile. “That’s one possible interpretation,” he agreed. “But let’s not forget the example of the humble frog.”

Matthew nodded to signify that he took the biochemist’s point. Earthly genomic analyses had shown that the relationship between genomic complexity and physical complexity wasn’t a simple one. In spite of their metamorphic capability, frogs were fairly low down on the complexity scale, but they had very bulky genomes because they maintained several parallel sets of genes for performing such seemingly simple tasks as determining the conditions in which their eggs could hatch. On the other hand, that same flexibility extended to patterns of development in early embryos—which was exactly the kind of versatility that might be an interesting consequence of the relative complexity of Tyrian genomes. “Have you made any progress figuring out what the presently unexpressed genes might be for?” he wanted to know.

“Yesterday, I would have had to say no,” Tang said. “Today …” He paused in order to wave a languid hand at his prize specimen before picking up the story. “It’s not just bigger than the other specimens I’ve seen. The mass-surface area considerations that affect growth and form are universal. It hasn’t got legs, so it doesn’t suffer from the supportive problems that affect so many Earthly animals, but the tentacles pose a similar problem. The muscular strength needed to move them increases geometrically in proportion to their length. That could be accomplished straightforwardly by adding muscular bulk, but it isn’t. The structural materials framing the muscle are different. Either a different set of genes has come into play, or the exons are teaming up according to a different pattern. Ike will suspect the latter, of course, but he’s primed to look for gene-nesting explanations. He and I will have to get together to see if we can fit the proteomics to the genomics.”

“That might help to explain why the local invertebrates don’t use a chitin-analogue in their exoskeletal components,” Matthew said. “The advantages of hardness and strength have to be set against the disadvantages of inflexibility. Earthly insects have to shed their exoskeletons if they want to get bigger. Here, where versatility is the order of the day, they use an entirely different set of molecules because it makes it easier to ring the changes.”

“Quite possibly,” Tang agreed. “It remains to be seen, of course, how flexible the system might be. So far, I’ve only had the opportunity to observe relatively minor variations of size and form. Until I find a much bigger giant, or manage to identify two radically different forms of the same chimerical cell-mix, it’s all conjecture.”

“Have you searched the flying-eye data for giant slugs that might be blown-up versions of this one?” Matthew asked.

“Not yet,” was the suitably guarded reply.

“But even if we keep the frog example in mind—
especially
if we keep the frog example in mind—it’s plausible that the extra genes in the DNA-analogue part of the genome include metamorphic options. Options that remain permanently in place, rather than simply guiding a growing individual through a fixed series of stages.”

“It’s all speculative, at present” Tang said. “But yes, those are the lines along which we’ve all been thinking. The parallel systems in frogs are all to do with reproduction—the options can determine the sex of hatchlings as well as facilitating development at a range of different temperatures—so it’s possible there’s a reproductive function here, if only we could figure out exactly how these creatures do reproduce. I’m no anatomist, but I can’t find anything resembling sex organs in this specimen or any of its kin. Andrei Lityansky undoubtedly told you about Bernal Delgado’s speculations about chimerical renewal and exchange, but I’m afraid that I haven’t been able to find any supportive evidence for the kinds of process he imagined. If the organisms are very long-lived, they might not bother to maintain their sex organs permanently—they might develop them temporarily just for the mating season. There are Earthly examples … but the simple fact is that we don’t know.”

“That thing
is
a chimera, I suppose,” Matthew said, pointing yet again at the creature in the biocontainment cell. “Is it a more complicated chimera than its smaller kin?”

“Oddly enough, no. When I began investigating the specimen I half-expected to find far more extensive chimerization than the smaller specimens exhibit, but it’s a mosaic of eight genetically distinct but phenotypically similar cell-types, which is exactly the same level of complexity as specimens with a tenth of its body mass, and less than some thumb-sized individuals of other kinds. Eight is by far the most frequent figure that turns up—four is only half as common, sixteen less than a quarter. Two crops up fairly regularly, but I haven’t yet found a thirty-two—or, for that matter, a singleton.”

“What about the mammal-analogues?” Matthew asked.

“The work that’s been done at Base One hasn’t turned up anything but fours and eights. That’s disappointing, in a way. There doesn’t seem to be any correlation between phenotypic complexity and chimerical complexity—but everything we’ve examined thus far has been a
simple
chimera in the sense that all the cells are closely related—often sibs or half-sibs. Again, it all comes back to reproduction. If they don’t grow temporary sex organs for the mating season they may well indulge in periodic radical experiments in chimerization, but …

“Until we catch them at it,” Matthew finished for him, “we have no way of knowing
what
they get up to.”

It wasn’t quite the way Tang would have put it, but he nodded agreement regardless.

“How much hidden potential are we talking about?” Matthew wanted to know. “Setting aside worries about the frog example, how versatile might these beasts be when they’re not cruising in neutral?”