Any long particle made up of an odd number of individual fermions would retain the first two fermionic properties, but if it also included any bosons, their presence would show up in the pattern of phase changes when the particle was rotated. A long particle with a wormhole sequence of "fermion-boson-fermion-fermion" would go out of phase and back like a simple fermion after one and two rotations, but a third rotation would bring it back into phase again immediately. Successive rotations could probe the wormhole's structure at ever greater depths: for each individual fermion in the chain it would take two rotations to restore the particle's phase, while for each boson it would take just one. As Orlando had put it—groping for a three-dimensional analogy when Yatima had started spouting group theory and topology—it was like sliding down into the particle's wormhole on the banister of a spiral staircase. Sometimes after going full circle, a twist in the banister left you upside down, so you had to go round once more before the staircase appeared right—way up again. Other times, a single turn left everything looking normal.

As the nanomachines put the finishing touched the apparatus, wiring the neutron source and detectors to the bays data link, Yatima thought of contacting Blanca. But the one time they'd met, the Voltaire clone had shown no interest whatsoever in vis dead Fomalhaut-self's ideas. Blanca had declined, everywhere, to rush the flesher equivalent—the de facto post-arrival standard adopted throughout the Diaspora—and as a consequence ve'd become rather isolated. Sinclair might have liked to witness the experiment, but he'd have to wait 82 years; he hadn't taken part in the Diaspora at all.

Yatima gestured at a switch on the side of the neutron source; it was just a scape object grafted onto their view of the machine, but throwing it would transmit the signal down to Lilliput to cycle the first neutron through. "Do you want to do the honors?"

Orlando hesitated. "I'm still not sure what I'm hoping for. Exotic physics from the Transmuters… or the entertainment value of seeing you try to squirm out of this if you're wrong."

Yatima smiled serenely. "The wonderful thing about hope is that it has absolutely no effect on anything. Just throw the switch."

Orlando stepped forward and did it. The display screen beside it—another scape object—was instantly filled with symbols scrolling past in an unreadable blur. Yatima had been expecting a short pattern, recurring after five or six rotations at most—or if the neutrons were sadly normal, just two. A few segments would have been enough to prove the point, but maybe the Transmuters had had no control over the total length.

Orlando said, "Is this equipment failure, or wild success?"

"Wild success, I hope."

Yatima sent the screen gestalt instructions to rewind. The start of the data showed the neutron slipping in and out of phase with repeated rotations:

-++-+-+++-+-++++-+-+-+-+++++…

Directly below was the interpretation: FbFFbbFFFbbbFFFFbbbb…

Orlando read aloud, "Fermion, boson, fermion, fermion, boson, boson…"

Yatima said, "It's not a hoax, I swear."

"I believe you." The counting went up to 126, then the pattern stopped and something far less decipherable took over. Orlando looked almost fearful. "It's a message. They've left us a message."

"We don't know that."

"It could be the equivalent of their whole polis library. Tied on a single neutron wormhole, like knots on a string." He was beaming unsteadily now; Yatima wondered if his embodiment software would let him pass out from shock.

"Or it might just be proof of artificiality. An improbable sequence, so no one mistakes this for a natural phenomenon and screws up their physics trying to explain it that way. Don't jump to conclusions."

Orlando nodded, and wiped his forehead with his palm. He gestured at the screen to scroll forward to the latest data; the torrent continued, but it was visibly slower. Each test for a different number of rotations had to he performed several times to get reliable statistics and after a billion rotations and an interference measurement, you couldn't just rotate the neutron one more time for test one-billion-and-one, you had to start again from scratch.

They waited for the pattern to recur. After twenty-two minutes, the neutron decayed without repeating itself. In theory, the resulting proton should have retained the same hidden structure, but Yatima hadn't made any provision to capture it, and the whole machine would have had to he rebuilt to handle a charged particle.

Ve instructed the analyzer to shift to a much higher rotation frequency. The second neutron rapidly yielded exactly the same sequence as the first, and survived long enough to start repeating, after six times ten-to-the-eighteenth segments. Six exabytes of data wasn't exactly a polis library, but it left room for a lot more than a maker's imprint or some idle subatomic graffiti.

The screen translated the sequence into Orlando's stylized spiral staircase, a twisted ribbon reminiscent of DNA, but far longer than any genome or mind seed. Until this moment, Yatima had never really felt the hand of an alien civilization here; the isotope signature was unambiguous, but too amorphous to convey anything more than its own artificiality. They'd found no ruins, no monuments, no shards—and it was impossible to say whether the oasis life had been the Transmuters' biological cousins, their artificial pets, or just an accident with no connection to them at all. But now the planet was revealed to be dense with artifacts older than any skyscraper or pyramid, richer than any papyrus or optical disk. And every picogram of atmospheric carbon dioxide held three hundred billion of them.

Ve turned to Orlando. "Do we spread the news now, or try for an interpretation first?" The library was bursting with pattern analysis software, three millennia's worth of attempts to he prepared for this moment. People had already run most of it on various Swift genomes, looking for hidden messages without success.

Orlando managed a conspiratorial grin. "It's not like breaking into a tomb. We can't damage this just by looking at it."

Yatima jumped to the xenolinguistics indexscape, a room full of display cases holding mock Rosetta stones, fragile scrolls and manuscripts, and quaint electromechanical code-breaking machines. Ve built a pipeline from the store of neutron data to a string of these analysis programs. Orlando had followed ver, and they stood in the carpeted room watching silently as a swarm of blue-white fireflies, representing the data, moved from icon to icon.

The twelfth icon in the chain was an ancient cathode ray tube display, representing an absurdly naive program that Yatima had only included because it would take so little time to run. The instant the fireflies alighted on its bakelite case, the screen burst into life.

The image began with a single, short vertical line, then zoomed out slowly to reveal dozens, then hundreds, of similar lines. Yatima didn't recognize the pattern, but the software had: the bottom end points of the lines marked the positions of stars—Voltaire and its backdrop from a certain angle, about fifty million years ago. Oddly enough, it wasn't a perspective view but an orthogonal projection. Did that say something about the Transmuters' perceptual system? Yatima caught verself; maps of the Earth had been made looking like everything from flattened orange peel to a reflection of the planet in a giant distorting mirror. None of them revealed a thing about fleshers' ordinary vision.

Orlando exhaled heavily. "Pixel arrays? It's that simple?" He sounded almost disappointed, but then he laughed, elated. "Good old two-dimensional images, changing with time! How's that for an antidote to abstractionism?" After a moment he added, "Even if it is just a fragment of the data." Yatima was receiving gestalt tags broadcast by the cathode-ray tube icon, packed with supplementary information, but Orlando was tortuously reading the same things in linear text from a translation window pasted into the scape by his exoself.