Incandescence

They scoured the region with their instruments, but this star's sole companion was a sparse disk of rubble, with all the fine dust that might normally have been expected blown away by the wind from the neighboring stars. No gas, no ice; just barren rock. With volatiles so rare, Rakesh thought, it must have been a challenge for the Aloof's engineering spores to scrape together the raw materials to reconstruct the whole ship, unless they'd developed femtomachines sophisticated enough to make transmuting the elements more efficient than scavenging for them.

The second candidate on their list had managed to hold on to even less detritus than the first. The winds from the new-born giants were not as strong here, but if any planets or asteroids worthy of the name had once accompanied this star, they had long ago been dislodged from their orbits by interfering neighbors. Rakesh had learned as a child that life could only thrive out in the disk, and however far the Steelmakers had progressed it was growing ever harder to see them as much of an exception to that parochial rule. Maybe life had flourished in this region, in some as yet undiscovered niche that had nothing to do with planets sitting in stable orbits around stars for billions of years; maybe the Aloof were descended from such creatures. The fact remained, though, that his cousins seemed to have hitched their fortunes to a way of life that simply couldn't last here.

The third star possessed a substantial asteroid belt, but still no planets. Rakesh thought, This is how it's going to be: sometimes a few more rocks, sometimes a few less. Each star's chaotic history of close encounters would sweep a slightly different range of orbits clean, but there'd always be a smattering of junk clinging on.

Parantham said calmly, "The isotope signature of most of these asteroids matches our rock."

Rakesh viewed the data. Point after point coincided, error bars overlapping. What's more, the models he ran rejected the notion that these asteroids had been born from the same gas cloud as the star they orbited. It looked as if they'd found the Interloper, and the shattered remnants of the Steelmakers' world.

Rakesh was shaken, though he knew he had no right to be surprised that the search had ended badly. The Interloper had dragged this world into ever more dangerous territory; the real miracle was that it had enjoyed such a long era of safety and stability around its birth star. "So this is their graveyard," he said.

"We don't know that," Parantham replied. "We know that the Steelmakers built at least one interplanetary probe. At some point they might have built star ships, or engineering spores. They might have left this world behind long before it was broken up."

Rakesh had his doubts that the Steelmakers — as a species, let alone a technological culture — could have survived their planet's capture by the Interloper. Still, it was possible that in the intervening hundred million years a second intelligent species had arisen in their place. In any case, he'd honor his promise and sift through the ruins. He owed it to the Steelmakers and whoever might have followed them to do his best to learn their history and bring it back to the Amalgam.

Dynamical models indicated that the Steelmakers' world had been tidally disrupted, rather than smashed apart by a head-on collision. A compact stellar remnant — most likely a neutron star — had passed through the system fifty million years before, coming close enough for the difference in its gravitational pull from one side of the planet to the other to tear asteroid-sized rocks right out of the mantle and send them fountaining into the sky. Though common sense made that sound like the work of a monstrously powerful force, the models suggested that the tidal stretching had only exceeded the planet's gravity by a modest amount, perhaps as little as fifty per cent. If there had been any hapless descendants of the Steelmakers around, the tidal force itself would have left them unscathed, but that would have been the least of their problems. Some might have survived the initial quakes, as the pressure bearing down on the planet's interior was lessened in places and strengthened elsewhere, fracturing the crust like the skin of a squeezed grape. Some would have felt their own weight growing, but not unbearably, and even where the tidal stretch turned gravity skyward, some might have had the presence of mind to grip something anchored securely to the ground and cling to life for a few more minutes as the air around them grew thinner. In the end, though, the ground itself had had nothing to hold it together against its own reversed weight, and the planet had simply disintegrated.