Blindsight

I still don't know if the fourth wave ever existed. I never saw any evidence of one, for whatever that's worth. We might have left them floundering back at Burns-Caulfield. Or maybe they followed us all the way to Big Ben, crept just close enough to see what we were up against, and turned tail before things got ugly.

I wonder if that's what happened. I wonder if they made it back home.

I look back now, and hope not.

* * *

A giant marshmallow kicked Theseus in the side. Down swung like a pendulum. Across the drum Szpindel yelped as if scalded; in the galley, cracking a bulb of hot coffee, I nearly was.

This is it, I thought. We got too close. They're hitting back.

"What the—"

A flicker on the party line as Bates linked from the bridge. "Main drive just kicked in. We're changing course."

"To what? Where? Whose orders?"

"Mine," Sarasti said, appearing above us.

Nobody spoke. Drifting into the drum through the stern hatchway: the sound of something grinding. I pinged Theseus resource-allocation stack. Fabrication was retooling itself for the mass production of doped ceramics.

Radiation shielding. Solid stuff, bulky and primitive, not the controlled magnetic fields we usually relied on.

The Gang emerged sleepy-eyed from their tent, Sascha grumbling, "What the fuck?"

"Watch." Sarasti took hold of ConSensus and shook it.

It was a blizzard, not a briefing: gravity wells and orbital trajectories, shear-stress simulations in thunderheads of ammonium and hydrogen, stereoscopic planetscapes buried under filters ranging from gamma to radio. I saw breakpoints and saddlepoints and unstable equilibria. I saw fold catastrophes plotted in five dimensions. My augments strained to rotate the information; my meaty half-brain struggled to understand the bottom line.

Something was hiding down there, in plain sight.

Ben's accretion belt still wasn't behaving. Its delinquency wasn't obvious; Sarasti hadn't had to plot every pebble and mountain and planetesimal to find the pattern, but he'd come close. And neither he nor the conjoined intelligence he shared with the Captain had been able to explain those trajectories as the mere aftermath of some past disturbance. The dust wasn't just settling; some of it marched downhill to the beat of something that even now reached out from the cloud-tops and pulled debris from orbit.

Not all that debris seemed to hit. Ben's equatorial regions flickered constantly with the light of meteorite impacts—much fainter than the bright wakes of the skimmers, and gone in the wink of an eye—but those frequency distributions didn't quite account for all the rocks that had fallen. It was almost as though, every now and then, some piece of incoming detritus simply vanished into a parallel universe.

Or got caught by something in this one. Something that circled Ben's equator every forty hours, almost low enough to graze the atmosphere. Something that didn't show up in visible light, or infrared, or radar. Something that might have remained pure hypothesis if a skimmer hadn't burned an incandescent trail across the atmosphere behind it when Theseus happened to be watching.

Sarasti threw that one dead center: a bright contrail streaking diagonally across Ben's perpetual nightscape, stuttering partway a degree or two to the left, stuttering back just before it passed from sight. Freeze-frame showed a beam of light frozen solid, a segment snapped from its midsection and jiggled just a hair out of alignment.

A segment nine kilometers long.

"It's cloaked," Sascha said, impressed.

"Not very well." Bates emerged from the forward hatch and sailed spinward. "Pretty obvious refractory artefact." She caught stairs halfway to the deck, used the torque of spin-against-spam to flip upright and plant her feet on the steps. "Why didn't we catch that before?"

"No backlight," Szpindel suggested.

"It's not just the contrail. Look at the clouds." Sure enough, Ben's cloudy backdrop showed the same subtle dislocation. Bates stepped onto the deck and headed for the conference table. "We should've seen this earlier."

"The other probes see no such artefact," Sarasti said. "This probe approaches from a wider angle. Twenty-seven degrees."

"Wider angle to what?" Sascha said.

"To the line," Bates murmured. "Between us and them."

It was all there on tactical: Theseus fell inwards along an obvious arc, but the probes we'd dispatched hadn't dicked around with Hohmann transfers: they'd burned straight down, their courses barely bending, all within a few degrees of the theoretical line connecting Ben to Theseus.

Except this one. This one had come in wide, and seen the trickery.

"The further from our bearing, the more obvious the discontinuity," Sarasti intoned. "Think it's clearly visible on any approach perpendicular to ours."

"So we're in a blind spot? We see it if we change course?"

Bates shook her head. "The blind spot's moving, Sascha. It's—"