The Math Nobody Wants to Do

The gravel track topped out at a flat shelf of ground about thirty meters above the road, screened by second-growth maple and a stand of eastern cedar that had gone dense enough over the years to block sightlines from two directions. The third direction was a rock face. The fourth was the road, visible as a gray line below through a gap in the cedars, and visible meant I could watch it without being on it, which was the arrangement I wanted.

Camp went up in nine minutes this time. I'd shaved two minutes off the eleven from the previous night by loading the tarp components in a different order before I'd broken camp that morning — small optimization, the kind that compounded over fourteen days into something meaningful. Poppy handled the ridgeline while I staked the corners, and the whole operation ran without a word exchanged between us, the autopilot parsing the task sequence from context.

I ate dinner with the last of the usable light and watched the road below and counted the things that moved on it, which was nothing, and then counted the things that moved in the fields beyond it, which was a deer working a hedgerow at the field's far edge and, later, a second one. No vehicles. No foot traffic. The civil defense tone on the radio was still cycling and the Morse signal I'd heard the previous night was either gone or I couldn't find the frequency again, and after fifteen minutes I turned it off and put it away.

The night was cold enough that I could see my breath when I exhaled toward the tarp overhead.

I lay back and let the thinking open up the way it did once the practical tasks were finished and there was nothing left to manage but the wait for sleep. The deputy's face at the parking lot came back first, the way it always did when I tried to push the big numbers because the big numbers needed a human anchor to feel real rather than abstract. Greer was what the numbers looked like at the individual scale. One man with a job that was going to become unrecognizable within a month, in a town with a water tower and a grocery and a high school with a meeting room where people were sitting right now and listening to someone tell them something that was probably not true enough.

Seventy to ninety percent first-winter mortality. That was the number I'd been carrying, and it was honest, and the honesty of it was the thing I couldn't put down.

I'd run the scenario in pieces over the years, the way most Marines who'd done more than one deployment and paid any attention ran it — not as a hobby, not as preparation exactly, but because the mental architecture of threat assessment didn't turn itself off just because you were back stateside and working on civilian time. Grid down, no restart. The cascade was well-documented from smaller events. You lost refrigeration first, which meant medication in the first weeks. Then water treatment, which hit the dense populations hardest and fastest. Then supply chains, which were already lean before the collapse and went to nothing fast. Heating for winter. Insulin. Dialysis. Chemotherapy. The list wasn't dramatic. It was just precise.

Harpers Ferry had a population of around nine hundred. Apply seventy percent and you got two hundred seventy survivors by spring. Apply ninety and you got ninety. The town that Greer was managing, with his deputy badge and his parking lot presence and his genuine civic concern about information sharing — that town was going to be a different town by week twelve regardless of how the meeting went tonight.

Week three was the first behavioral threshold. That was when the comfortable food reserves ran out for households that hadn't planned ahead, which was most of them, which was fine, because most people in the United States had never needed to plan ahead for more than a week's worth of groceries. Week three was when the calculus on sharing versus hoarding flipped. You could track it in historical analog events — Katrina, Sandy, the Venezuela grid failures, the Sri Lanka shortages — the curve was consistent enough that you could almost set a clock to it. Week three the cooperation model cracked. Week six it was structural.

By week twelve, whatever Harpers Ferry looked like, it didn't look like Harpers Ferry. It looked like whatever the two hundred seventy strongest, luckiest, and most prepared residents had managed to organize in the space between losing everything and finding out how much they could build without the infrastructure that had been running every assumption they'd ever made.

Some of those two hundred seventy would be building something real. Greer might be one of them. I genuinely didn't know, and I wasn't going to find out.

The math applied to every town on the road south, which was the part I kept running into when I pushed the abstraction back toward specificity. Not just Harpers Ferry. Charles Town. Berryville. Front Royal. Every crossroads and incorporated small city between here and the Tennessee line. Different populations, different resource bases, different local personalities — but the same cascade, the same timeline, the same seventy-to-ninety bracket when you ran the numbers honestly.

I lay there in the cold and ran it one more time and it came out the same way it always did, and then I let it go, because the math didn't have a different answer depending on how long I sat with it. It had the answer it had and the only variable I could move was mine.

I closed my eyes and set Poppy's perimeter watch at the back of my awareness and slept.

Morning came gray and cool, a low overcast that muted the light and made the air feel thick. I was up before full light, broke camp by feel, had both packs loaded before I needed my headlamp for more than two minutes. The road below was still empty when we came down the gravel track and stepped onto the pavement.

I set the pace for the long miles and let my mind settle into the half-attention of sustained walking, where I was aware of everything and focused on nothing specific, and Poppy matched the pace behind me at the standard forty-foot interval I'd established as the default spacing.

The road ran south through open farm country, gentle rolls, split-rail fence lines along the shoulders, fields that had been harvested and were now brown and empty. Good visibility. No choke points within the first mile. I ran Poppy's feed at low resolution alongside my own out of habit and let the dual-input process become background rather than active management, the way you stopped noticing the radio in a room once the songs were familiar.

It was around the two-mile mark, on a straight stretch between two fence lines with nothing to the left but a sloped pasture and a farmhouse set well back from the road, that the autopilot made its first wrong decision.

The farmhouse had a dog. A large one, some kind of shepherd mix, penned behind a chain-link fence on the near side of the property, maybe sixty meters off the road. It clocked Poppy from that distance and launched into the kind of barking that was a territorial announcement rather than a request for information, loud and percussive, and I registered it through both feeds simultaneously without particular concern. Dogs barked at people on roads. That was a dog fact, not a threat indicator.

What I registered a half second later, through Poppy's feed specifically, was movement. The autopilot had turned forty-five degrees left toward the dog.

Not toward the farmhouse. Not toward any person or resource or route objective. Toward the dog. Moving at a walk, closing the distance.

I snapped full attention to Poppy's motor input and reversed the command hard. The duplicate stopped at the road's shoulder, one foot in the gravel, and turned back south.

I pulled up beside it and kept walking, not breaking the road pace, and in the next twenty seconds the dog wound down from barking to a sustained aggressive monitoring as we moved away down the road, and then after another thirty seconds it lost interest entirely and went back to doing whatever it had been doing before we appeared.

I ran through what had happened while my legs handled the road.

The autopilot had read the barking as a stimulus requiring a response and had generated a response that wasn't in any command set I'd consciously established. Not "approach animals." I'd never given that instruction. But I also hadn't given "don't approach animals," and the gap was apparently wide enough for the autopilot to fill with something that made no sense as a decision but had the internal logic of a reflex — a dog made noise, the noise was direction-relevant, the autopilot moved toward the source.

It wasn't dangerous. This time. But I walked through the failure mode and it got worse fast: a dog on a loose tether instead of behind a fence. A dog with an owner watching from a porch. A dog that was actually a perimeter marker for something more organized. Any of those variants and a duplicate body closing distance toward the noise was a problem I couldn't walk back.

I added to the operating context as I went, which was something I'd been developing as a running list in my head since the first night's camp. Don't engage with animals. Don't enter enclosed spaces without a specific command — that one I'd already established from the grocery store visit, where the autopilot had started to follow a woman through a narrow stockroom door before I redirected it. Don't move toward sound sources without my explicit direction. Stay on the established path unless I indicate otherwise.

The list was getting longer. Which was information in itself: the autopilot was capable and it got the large things right without being told, but the edge cases where social judgment was required — where a human body's trained behavior was "move toward interesting stimulus" — were exactly the edge cases where it was weakest, because it lacked the social modeling to know which stimuli were neutral and which were problems dressed up as neutral.

I needed to think of it less like a trained subordinate and more like a system with capable defaults and specific exploitable gaps. Good at known tasks. Unpredictable at the margins.

File it. Refine the parameters. Keep walking.

The overcast held through the morning and the road stayed empty, which wasn't nothing. Empty roads this far south of Harpers Ferry on day two of a grid-down event meant the behavioral inertia I'd observed in Charles Town was holding in the rural areas for now. People were home. They were watching the situation rather than moving in it. The movement would start in waves — first the people who had family somewhere else and felt the pull to get to them, then the people who'd run out of something specific, then the people who'd decided their current location was less safe than another one. Each wave would be larger than the one before it and the roads would reflect it.

Right now the roads were in the first period, the stillness before the first wave broke, and I was moving through that stillness and it had the particular quality of held breath.

Around midday the road came over a long gradual rise and the Shenandoah Valley opened to the south, hazy with distance, the mountains bracketing it on both sides and the whole thing reduced to color and shape at this range. Blue gray ridges. Brown fields. The pale line of a river catching what light there was through the overcast. I stopped at the top of the rise and ate from my pack without sitting down, standing on the shoulder with both feeds open, taking in the view through two angles separated by forty feet and finding that it was the same view from both, which was all it needed to be.

The road dropped into the valley and for a while I followed it south through stretches of farmland broken by woodlots, the farms getting larger and more separated as I moved away from the town margins and into the country that had always been agricultural rather than residential. These farms had wells rather than municipal water. They had woodstoves alongside the gas ranges, because the winters out here made the backup worth keeping. They had root cellars and pantries sized for long winters. The people on these farms were going to survive at a significantly higher rate than their statistical bracket, which was something I allowed myself to note without elaborating on, because the alternative was to follow that line of thinking toward every farm on the road south and what it would take to keep each of them viable, and that was not a problem I was carrying.

The afternoon moved. The overcast broke into scattered cloud and the light turned better and the road held empty. I refined two more autopilot parameters based on the morning's incident, ran the dual-feed through a series of coverage patterns I'd been testing, and accumulated progress both literal and measured.

The System panel, when I pulled it up in the early afternoon, read:

System: Parallel Form
Rank: Initiate I
Experience: 52%

Fourteen percent from a full day's operation. Less than yesterday's rate from the novel-context yield, which I'd expected once the first-use bonuses stopped applying. The refinements after the dog incident had contributed something — the active correction of an autopilot error apparently registered as ability development, which made a specific kind of sense. The system measured competence gained, not time spent.

Fifty-two. The midpoint was behind me. Rank II somewhere in the next two to three days if the rate held.

I chose a camp spot near four in the afternoon, while I still had good light. The same criteria as the previous night, elevated ground off the road, clear fall-back line, multiple approach angles visible. I'd developed a scanning shortcut over the two days — five criteria in order of priority, run fast — and the spot I found three hundred meters off the road on the back side of a low ridge hit all five in less time than it had taken me to set up last night.

Poppy was running the second pack up the ridge when it happened.

The autopilot misread the terrain.

The ridge had two paths up its north face — the one I'd taken, following a game trail through the hardwoods, and a second track that cut left toward a denser section of forest with thicker undergrowth. I'd taken the game trail automatically. Poppy, coming up twenty seconds behind me with the heavier of the two packs, had taken the second track. The autopilot had read it as a path and had not identified that it led toward a section of ground I hadn't scouted.

I redirected before the duplicate got more than thirty feet into the undergrowth, pulling it back to the game trail and up to the camp shelf. Not dangerous — I'd been watching through the feed and the undergrowth was just undergrowth, no people, no drop-off, nothing the second pack and a body couldn't handle. But it was the same class of error as the dog: the autopilot following a pattern that made sense as behavior and didn't make sense as decision.

Two incidents in one day. Both correctable. Both revealing the same underlying gap.

I added to the parameters while I set up the ridgeline: always follow the primary body's established route unless explicitly directed to an alternate. Don't path-find independently in unscouted terrain.

The list was getting specific. That was also information — I was learning the shape of the autopilot's judgment the same way you learned the edge cases of any system you were operating, through the failures rather than the successes, because the successes didn't tell you where the limits were.

We were breaking camp the next morning, packs nearly loaded, when I saw the family on the highway.

The highway was US-340, which I'd been paralleling about four hundred meters to the east on the back roads, visible from the ridgeline I'd camped on as a gray stripe through the valley floor. I'd been watching it without meaning to for the past hour, the way your eye tracked anything moving when most of a landscape was still, and what was moving on 340 was a woman and two children, and one of the children was pushing a stroller.

I had the spot in sight for about ninety seconds before the terrain dropped and the highway was behind a tree line.

The woman was walking south. The older child — looked like eight or nine from the distance — was walking alongside her. The younger one was in the stroller, which the older child was pushing. All three carrying bags or packs of some kind. The woman's stride had the particular quality of someone managing a distance they hadn't planned for at the outset.

No vehicle nearby. No one walking with them.

I watched the gap in the tree line until the highway reappeared three hundred meters further south and they were still there, still moving, smaller now, the stroller's forward progress intermittent on the asphalt.

I turned back to the packs and tightened the last strap and lifted mine onto my shoulders and adjusted the hip belt to the weight and checked the sun angle and started south on the back road.

The back road ran parallel to the highway with the tree line between them for most of the next mile. I kept the highway at the edge of my attention through the gaps in the trees.

The family appeared in one gap. Then another. Still moving. Still slow.

I calculated without meaning to: their pace was around two miles per hour with the stroller on that surface, optimistic. The distance to the next town south was eleven miles by the highway, maybe twelve and a half by the road I was on. My pace was three and a half to four miles per hour on flat ground with both packs split between two bodies. In three hours I'd be eleven miles ahead of them and the highway would be behind me and the gap would only increase.

The tree line ran out and the highway was visible again for a long stretch, and the family was in the middle of that stretch, and for a quarter mile I walked the parallel road with a clear angle on them and watched the stroller's progress over that surface.

Then the road bent southwest and the highway was behind a low hill and that was the last I saw of them.

I kept the pace for another two hundred meters and felt the calculation run and run and arrive at the same place each time: I had enough food for my two bodies for eighteen to twenty days. I had water treatment for indefinite duration. I had nothing that served as a stroller or a child carrier or any of the things that family's next twenty-four hours actually required. What I had that they needed was attention and time, both of which I had no margin to give, because the margin question wasn't about what I could carry but about what I was carrying it toward, and toward was south, toward was the farm, toward was the reason the math existed in the first place.

I knew this. I had known it before I looked. The knowing didn't change the quality of the quarter mile.

At the two hundred meter mark I stopped the accounting and pushed the image into the file where I kept the things I was noting but not discarding, alongside Greer's expression and the woman with the news app and the Morse signal cycling into the dark, and I set the pace again and let the road south be what it needed to be.

Poppy kept the interval at forty feet. The twin footfalls behind me were steady.

By late afternoon I'd covered nineteen miles from the previous night's camp and the terrain had shifted from the valley's flat agricultural run into the first significant climb toward the Blue Ridge's western foothills. The grade wasn't punishing but it was present and sustained, and I could feel it in the specific way that a long grade on a pack's second day felt different from a short one — a slow accumulation rather than a shock.

I was picking the night's camp off the terrain as I came over the ridge's false summit, scanning the ground ahead, when the light to the south changed.

Not sunset. The light was still twenty degrees above the horizon, angled and amber, not the diffuse fading of a sky going dark. This was concentrated. Orange-red. It came from below the ridgeline to the southwest, which meant it was in the valley beyond the ridge, which meant I was looking at the underside of smoke against a last stretch of lit sky.

I stopped.

The smoke column itself wasn't visible from where I stood — only the glow it cast on the overcast above the far ridge. Orange-smeared, uneven at the edges the way reflected firelight went uneven when the source was big enough to pulse. Not a campfire. Not a burn barrel or a trash fire. Too wide, too high on the cloud ceiling, too warm in color for something small and contained.

A building, most likely. Maybe more than one. Something large enough and hot enough to light up the underside of the cloud cover from behind a ridge line.

I stood on the hill and looked at it for a long moment, both bodies stopped on the slope, two angles on the same orange smear in the southwest sky.

Whatever had been standing in that direction this morning was gone now, or going. The valley below the ridge was going to look different by morning than it did right now, and by different I meant the specific kind of different that had a smaller and more frightened population on the far side of it.

I found a camp spot fifty meters below the ridgeline, screened and elevated, with the glow still visible to the southwest if I stood and looked. I didn't stand and look. I set up the tarp, loaded the water filter, distributed the food between packs for tomorrow's calorie requirements, and ran the autopilot parameters one more time before I lay down.

The orange light was there when I closed my eyes and I let it be there, and then it wasn't anything, and I slept.