Greg Egan: Incandescence

«Yet you emerged unscathed?»

«I believe I'm intact,» Lahl replied. She added mischievously, «Though I would think that, wouldn't I?»

Three hundred millennia ago, certain brash citizens of the Amalgam had studied the Aloof's data traffic, deciphered its basic protocols, and constructed links between the two networks. This unilateral act of bridge-building had apparently been tolerated by the Aloof, albeit with only a trickle of data passing through, since few people were willing to trust the short cut. The Amalgam had tried many times to extend its own physical infrastructure into the same territory, but the Aloof had calmly and methodically reversed the trajectory of every spore.

Csi said, «I think I would have arranged for a suitably located backup to wake, and attend the reunion on my behalf instead.»

«That would have been grossly discourteous,» Lahl explained. «And to have the slightest chance of pulling it off, I would have needed to start planning about sixty millennia ago. If I'd had that much foresight, I would never have ended up cutting things so fine in the first place.»

The table fell silent as the four of them contemplated the risk she'd taken. The Aloof had never been known to act maliciously — even the insentient engineering spores they'd swatted back out of the bulge had been left unharmed — but their stubborn refusal to communicate gave them an aura, if not of danger, at the very least of unaccountability. Worse, the part of their network accessible to the Amalgam did not carry quantum data, so the Amalgam's standard protocols — which rendered it physically impossible for an eavesdropper to decipher a transmission, or to alter it without detection — could not be employed. That problem had been addressed, in part, by distributing matched pairs of quantum keys around the edge of the bulge via the Amalgam's own network, creating stockpiles that could be used to encrypt the classical data of travelers taking the short cut. If demand for the keys outstripped supply, though, it could take a while for the stockpiles to be replenished.

Rakesh said, «The explorer you mentioned: did she take the same route? Is that how you met?»

«Explorer?»

«Didn't you say that a third party found this uncatalogued DNA world?»

«They found evidence for it,» Lahl said. «Not the world itself, as far as I know.»

Rakesh was perplexed. «As far as you know?»

«The Aloof embodied me,» Lahl explained, «deep inside their territory. I was shown a meteor, which appeared to be a fragment of a planetary crust ejected by an impact event. Inside, it was riddled with DNA.»

«So you've met them?» Viya asked, incredulous now. «You've met the Aloof?»

«Of course not,» Lahl replied. «They kept me at arm's length. They woke me in a small interstellar habitat, well suited to my customary embodiment, alone with this rock and the instruments needed to examine it. The short cut had bought me five thousand years' grace, so I had no qualms about spending a few days obliging my hosts, and satisfying my own curiosity. The cells inside the meteor were all dead, but there was enough intact genetic material to reveal that it hadn't been blasted straight off the surface of any of the known DNA worlds. It was from a mature divergent branch of the panspermia. It must have originated on a world of its own.»

«Do you know where they collected it?» Parantham asked. «They would have had to travel out of the bulge, surely?»

Lahl said, «There was a map showing where they'd found it: not far from the place where I was examining it. Particle tracks in the outer layers of the rock seemed to bear that out; it looked as if it had been exposed to ambient radiation levels for about fifty million years. And as best as I could date the impact event, that was about fifty million years ago, too.»

Viya frowned. «That makes no sense. For ejecta to get from a typical DNA world down into the bulge would take at least half a billion years.»

«Exactly,» Lahl said. «So it can't be from a typical DNA world. The planetary system itself must be deep in the Aloof's territory.»

Rakesh felt a thrill of astonishment, though he was far from convinced that Lahl's conclusion was the right one. All eleven panspermias were believed to have originated at middle radii in the galactic disk, between twenty and thirty thousand light years from the center. Certainly, the worlds on which the eleven replicators were known to have thrived were confined to that zone, where the galactic chemistry favored the formation of suitable planets, the radiation levels were reasonably low, and such biosphere-sterilizing calamities as supernovae were relatively rare. The process by which collision ejecta had spread the replicators between star systems was supposedly well understood, and though nothing ruled out the possibility of debris carrying DNA-based micro-organisms all the way down to the galactic bulge, no one would have expected them to gain a foothold there.

«Perhaps the Aloof were showing you their cousins,» Parantham suggested. «Perhaps this was their first attempt to introduce themselves.» It was widely assumed that the Aloof had been born in the disk, like everyone else, and migrated to the bulge before any other civilization had traveled widely enough to encounter them.

Lahl shrugged. «If they'd wished to convey something like that, they could have made themselves clearer. They deciphered my transmission and embodied me; there was nothing mysterious to them in my nature to stand in the way of communication.»

Csi said, «I don't doubt that they deciphered you, but are you sure you were embodied?» He spread his arms, taking in the five of them and the whole elaborate scape. The node, in reality, was a few cubic meters of processor, drifting through interstellar space. There was no mesa, there was no jungle, nor any of the alternatives that any of them were perceiving.

«Of course I'm not sure,» Lahl conceded. «And even if I was embodied, the meteor itself could have been a carefully manufactured fake, or the instruments I was supplied with could have been contrived to mislead me. But I can't see the point in that kind of deception. Why spread misinformation about the DNA panspermia among people to whom you're largely indifferent?»

«Why spread valid information, either?» Rakesh mused. «I'm surprised they didn't just lob this out of the bulge, muttering about yet another incursion by those awful disk people.»

«Lob it where, though?» Csi replied. «And if the planet it came from really does lie in the bulge, this 'incursion' probably predates their own presence.»

Lahl regarded them both reprovingly, as if she considered these comments to be willfully obtuse. She said, «I believe they felt obliged to tell someone, to get the word out. In spite of their refusal to communicate with us on any other topic, I believe they considered it their duty to pass this information on to us, to make of it what we will.»

«As you considered it your own duty to hand the message on to a descendant of the appropriate replicator?» Rakesh suggested.

«Exactly.»

Rakesh was on the verge of pointing out that it was somewhat parochial of her to assume that the Aloof would share her sense of obligation, but then it struck him that, out of all the travelers who'd taken the short cut, the Aloof might have chosen Lahl precisely because she was the most likely to understand, and act upon, their intentions.

Whatever the original cues being translated, Lahl's face had taken on a subtly challenging aspect, as if she was waiting for Rakesh to make clear to her whether or not she'd been wasting her time.

Rakesh was still unsure of the verdict himself. Was this his calling? He had never thought of the bulge as a place of genuine mysteries. Many individual citizens of the Amalgam were every bit as private as the Aloof; he had no idea what went on inside their homes, but his ignorance hardly transformed those places into unexplored territory. The higher the gate, the more manicured the garden.