Incandescence

Rakesh wondered if this leaning tower had been crafted to take account of its inevitable inclination. The interior of the Ark they'd visited had been essentially weightless, but here the orbit, fifty thousand kilometers from the neutron star, was small enough for tidal forces to be felt. While they waited for the surveyor probes, he summoned up a map of that other Ark to see which directions its makers had expected to be "up" and "down". It looked as if they'd hedged their bets: most chambers tended to be almost spherical, with no special orientation required to make particular surfaces work as floors. Similarly, the tunnels sloped in all directions. The makers had been prepared for some uncertainty, but they had clearly not expected the tidal gravity to grow strong enough to dictate the lives of the inhabitants. They had trusted the wind-based buoyancy to keep the Arks in comfortable orbits, and in this case they'd been proven right: the strongest that the tidal gravity would reach here, augmented by centrifugal force from its spin, would be about one sixth the surface gravity of the home world.

The surveyor probes reached their target. Rakesh watched anxiously as the neutrino tomograph slowly accumulated details, a solid labyrinth emerging from fog. The layout was not a tunnel-by-tunnel copy of the interior of the other Ark, but it was very similar, as were the density gradients in the walls. Here, those gradients could achieve their purpose: models showed the wind being scattered into the interior, spreading nutrients deep into the dead zone around the Ark's center where the plasma orbited at the same velocity as the habitat itself. In fact, the main difference the scan showed from the Ark they'd left behind lay in the center; where the last one had been full of rubble and unrepaired cracks, this Ark was in pristine condition.

The probes added an analysis of the Ark's thermal budget, which showed that a substantial fraction of the energy from the wind was being degraded into heat, in a manner that turbulence alone could not explain. On that basis, the biomass within appeared to be at least ten thousand times more than its barren sibling had contained.

Parantham said, "Let's see if anyone wants to talk to us." She broadcast a greeting from one of the probes, sweeping across the spectrum from the longest practical wavelengths down to far infrared. The plasma of the accretion disk stirred by the neutron star's magnetic field would not make for ideal radio reception, but shorter wavelengths would have no chance of penetrating the walls, and there were no visible external antennas or detectors that they could target. The other Ark had contained stretches of conductive wire, but if they had been part of the original design here they must have been broken up and dispersed. Perhaps that was a sign of technological change rather than decay or disrepair, with the old infrastructure being cannibalized for other purposes.

Rakesh said, "I'm loath to barge in until we've given them a chance to respond. It's hard to know how to warn them that we're coming when they don't seem to be looking outward at all, but we should at least try."

"That sounds reasonable," Parantham agreed.

Was it reasonable to enter this place at all? Rakesh tried to step back from his own agenda and ask the question objectively. Whether or not the Ark contained the descendants of a single cultural lineage stretching all the way back to the Steelmakers, these creatures or their ancestors had already suffered greatly from forces beyond their control. Weren't they entitled to do their best to shut out the universe and make their own lives inside this cocoon? It was true that the Amalgam could offer them far greater security than the most stable orbit in this perilous neighborhood, but it would be naive to think that contact itself would be a neutral experience. Out in the disk, the Amalgam had usually waited for cultures to develop interstellar travel for themselves before making contact with them; the exceptions had often been messy.

He turned to Parantham. "Assuming there's someone in there, why can't the Aloof keep them safe? Do you think they could really have been unaware of this place until we came here?"

"We don't know that they're not looking after them," she countered. "Maybe they're tweaking all the local stellar orbits, even as we speak. Maybe they've wrapped their giant hands around this spark of life to shield it from harm, just as meticulously as they've shielded the bulge from intruders."

"Then why are we here? What do they expect us to do?"

Parantham shook her head. "I could spin some half-plausible theory about them hunting for companions for these lonely foundlings, but the truth is I really don't know. It's not our responsibility to read their minds, though; our responsibility is to whoever is inside that Ark."