There's another platform ahead. Twenty rungs up. Roughly four hundred meters from the bottom. "What?" I'm talking to myself—that's not good news. I raise my right hand. Yes, it's a platform.

The next thing I know, I'm sitting on the platform, my legs dangling over the abyss, and I have no clear recollection of how I got here. I must have had another fugue moment. I shudder, my blood running cold at the realization.

I look round. This platform is just like the last one, right down to the door with the handwheel set in it two meters up the tunnel. Which means either I'm shit out of luck, or—well, I can try the door, at least. If it doesn't work, I can rest up. Then it's either up or down, heads or tails. I really don't think I can make another climb until my abused muscles have had some time to recover, and I didn't bring water or food. So I guess it's down, and down and down and back into the depths of Yourdon's little totalitarian fantasy.

Unless I let go of the ladder.

Or the door opens.

I take a kilosecond to rest up before I approach the door. When I spin the wheel one-handed, it smoothly winds up momentum, then there's a sigh of long-seated gaskets as it pulls away from the frame and swings out to one side. I look through the opening and see a universe that doesn't make any kind of sense to my eyes.

The floor in front of the doorway is flat, slightly rough, with a grayish stippled regularity typical of a high-grip paving system. The segments are Penrose tiles, presumably laid out by a walking assembler that crawled across the inner surface of this gigantic cylindrical space, never recrossing its own path as it vomited out the floor. Above my head there's a grayish ceiling that curves in the far distance to meet the upturned bowl of the horizon. Fine needles of diamond stab from the floor to the roof, holding heaven and earth apart. The door I've just stepped out of is set in the base of one of the needles—they're huge, and they're a long way apart.

This is probably an interdeck, an interstitial support space between the inhabited floors. Or it's a deck that hasn't been linked into the manifold of T-gates, terraformed and tamed and occupied. At a guess I've climbed right through Yourdon's security cordon, a level left open to vacuum. If I'd gone down I'd have found . . . what? Maybe a level where the experimenters live, where they're working on the upgraded Curious Yellow. Or just as likely, another vacuum level.

My knees feel like rubber. I lean against the outer wall of the radial tube I've just climbed, feeling completely exhausted. I look up at the ceiling, almost half a kilometer up, and realize just how little it curves and how wide the basin of reality is. There are clouds in here, collecting near the tops of some of the needles. The air is slightly misty and smells of dry yeast. Strange monochromatic humps in the floor suggest hills and berms—mass reserves waiting for the giant habitat assemblers to go to work on them. I try to identify the end caps of the cylinder, but they're lost in the haze, several tens of kilometers away. The light is coming from thousands of tiny bright points in the ceiling.

I could starve to death in this place long before I could walk out of it.

I try to rest up for a while, but unease prods me into premature motion. I know I need to try and accommodate this fatigue, but there's an edge of panic whenever I think about Kay, or the consequences of the thing lurking in my head that (I'm half-convinced) is causing these blackouts. There's not a lot I can do, except stay with the ladder and hope to find something more promising on the next deck up—almost a kilometer above my head. But I don't think I'd make it.

I stumble away from the ladder, heading toward the nearest berm. Maybe there'll be some emotional machinery near there that I'll be able to communicate with, something from outside YFH-Polity's frontier that'll be able to put me in touch with reality. I try my netlink, but it's dull and frozen, showing nothing but a crashed listing of point scores allocated to my cohort. Curious Yellow, I think dully. That's why I can't hear Sam when he says * * *: the score-tracking system is based on Curious Yellow.

A couple hundred meters from the berm I see signs of life. Something about the size of a taxi, consisting of loosely coupled rods and spheres, is hunching up over the crest of the deposit. It extends tubular sensors in my direction, then vaults over the crest of the hill, sensors blurring into iridescent disks, ball-and-rod assemblies spinning on its back. The balls are growing and thinning, unfolding like cauliflower heads that glow with a diffractive sheen. I stop and wait for it to arrive. I guess it's some kind of specialized biome construction supervisor, an intelligent gardener. There is absolutely nothing I could do to stop it from killing me if it's hostile—I might as well attack a tank with a blunt carving knife—but that's relatively unlikely. Knowing that doesn't make waiting easy, though.

It closes intimidatingly rapidly but rolls to a stop about three meters away from me. "Hello," I say, "do you have a language facility?"

The gardener draws itself up until it looms over me. Florets open and close, buzzing faintly. "Who are you and what are you doing here?"

I relax very slightly. "I'm Robin." The name feels odd, unfamiliar. "What polity is this?"

It buzzes and clicks to itself, flattening slightly at the top like a puzzled cobra. "Hello, Robin. This zone is no polity. It is ballast sector eighty nine, aboard the MASucker Harvest Lore. It is not an inhabitable biome. What are you doing here?"

No polity. I'm on a MASucker. Which means there'll probably only be one longjump gate on the whole ship, heavily firewalled  . . . I close my eyes and try not to sway on my feet. "I am trying to locate legal authorities to whom I can report a serious crime. Mass identity theft. If this isn't a polity, what is it?"

"I am not authorized to tell you. You are Robin. I am required to ask you: How did you get here? You are showing signs of physical distress. Do you require medical attention?"

I attempt to open my eyes, but they're not responding. "Help," I try to say. Then my eyes open, and I'm back on the ladder, hanging off it by one hand, feet dangling over the abyss of an infinite cylinder, but there are no rungs and there's another tube nested inside this one, stippled with a myriad of tiny points of light, and something is comingout of the wall to lean over me. "Help," I repeat, as the thing bends toward me.

"I will alert the Kapitan's lodge."

Darkness.

WE declared victory within the local manifold ten megasecs ago, and the magnitude of the reconstruction headache is just beginning to sink in. We've driven Curious Yellow back into its box and broken up the quisling dictatorships that thrived under it. But the war isn't over until a restart is out of the question. And that's an entirely different matter.

"The problem is, about half of the Provisional Government have vanished," Sanni—now a very senior colonel—tells me. (We're in a staff meeting room in MilSpace, cramped and beige and securely anonymized.) "The high-profile arrests are all very well, but where are the others?" She doesn't sound happy.

"They can't just vanish. Not without leaving some kind of traces, surely?" That's Al, the long-suffering gofer who keeps our research team in touch with the operational requirements group and headquarters' Received Instructions Interpretation Unit, whose job is to make sense of the oracular statements our Exultant patron occasionally offers. "There are a lot of scores to settle."

"It's a lot easier to slip through the cracks than it used to be," Sanni explains patiently. "Back when the Republic was unitary it could track identities effectively. But since the end of Is, we've been left with a myriad of self-contained polities, not all of which will talk to each other. Their internal data models aren't transitive. There could be any number of inconsistencies out there, and we can't normalize for them."