It took hours of slowly twisting, turning, and backtracking to finally reach an open space. This one had an open access hatch. I’d passed by several of these already, not realizing what they were. When closed, they looked a lot like the tool and equipment lockers that were spaced out every so often in the tunnels.

This one led to the the Oxygen Farm. At least, that’s what the diagram on the bulkhead called it. “Oxygen Farm C.”

Fortunately this place had been designed with zero-g in mind. Instead of open vats of algae there were various trays connected to the ventilation system and covered by a thin membrane that allowed the algae to sip the carbon dioxide from the air and release oxygen.

Dozens of these trays were stacked atop each other, covering one entire wall of the null ball stadium sized space. The ceiling was low, though, making it seem even longer. I could stand upright, but I could also touch the ceiling without even stretching.

After a moment, I realized what was bothering me about the place. It was too clean. Like the maintenance tunnel for the most part, the oxygen farm was completely spotless. No floating debris, no nests, no zombie piles of trash and bone fragments.

No zombies, already dead or otherwise.

I closed the maintenance hatch behind me. If zombies had not been here yet, there was no sense leaving it open for the ones that might still be in the tunnels to wander in. And just having zombies in the Oxygen Farm, let alone fighting them here...

That sounded like a spectacularly bad idea.

I still only had one and a half magazines for my pistol. It hadn’t seen much use since the zombies on the ship, but you never knew. Absent a situation where they all packed together tightly like the stairwell, I couldn’t kill them all in one go. And right now, I doubted I could drain anything at all.

Somehow, incomprehensibly, the pressure and pain got worse as I went. My vision swam as the pain spiked in my head for a moment and I stumbled to a halt, leaning on the bulkhead to steady myself.

I forced myself to take a step forward. Then another. There was no time left to rest. Either I made it to a power source and purged, or the bloat would somehow cripple me. Then it would be a race between dehydration and whatever damage the nanites caused to see which one would kill me first.

The only other door in the room was almost exactly halfway down. I was in no rush to get out of there. Well, I was. But running was out of the question at that moment in time. Sneaking was just barely possible.

Making it back safely to Security Medical was the first step. With all the noise I’d been making back at the warehouse there was at least a chance that they’d made it out undiscovered. Experiment Number One was no doubt bonking someone over the head with a bottle if it wasn’t asleep.

Either the two survivors were alive or they were not. If they were alive, they might have made it to Security Medical, and they might not. And if they had made it to Security Medical, either they can and would help, or they would not.

And if I could not get their help one way or the other, that meant I would have to somehow learn how to pilot a ship. Preferably within a matter of days. Considering that pilots needed years of school and training before they were trusted with other human lives and multi-trillion credit spacecraft that seemed to be a rather tall order.

I knew of precisely one ship at the dock that was clear of zombies. That one was in poor condition, with only one working airlock. Well, it might have been in great condition otherwise, but the many red and amber blinking lights on the bridge argued otherwise.

Other than that, there were the other freighters, the big gas tanker, and the biggest freighter. The other small ships were probably too small. At least, that was my assumption.

Verification would have to wait until I had access to the data again. And hopefully, someone with the experience to understand said data.

The door opened into a tiny room the size of a closet with a ladder built into the wall. I made sure to shut both the door and the access hatch behind me once I climbed out of the hole to keep the zombies out.

The lower engineering level was full of machines. That, I should have realized ahead of time. But these were absolutely massive machines, towering above me and long as city blocks. Gray wisps of steam escaped here and there to be caught in the wind that rushed through the gaps between.

I hadn’t expected it to be so loud, either. Over the rush of the wind were hissing, clanking, humming, and something like the thunder of rail freight that I could feel in my chest.

The source of at least some of the noise were the large spidery maintenance bots that climbed over the machines, tapping here and there, adjusting something, pulling a piece out and putting another back in according to whatever program their code minds directed them to. There were a dozen, at least, in view.

What I needed though, that wasn’t in view. A compatible power source. None of the giant machine blocks had the distinctive look of modern power generation, no containment bottles and pipes.

The thunderous noise suddenly grew louder and the deck began to vibrate under my feet. I looked around to see the source of the noise. Something like a giant freight train hurtled by in the gap to my right. It was taller than I expected, probably three stories tall at least, and its breeze from its passage tugged at my clothes and threatened to send me tumbling. I held myself in place with one foot hooking the ladder I’d just climbed from the Oxygen Farm.

Note to self. Watch out for traffic.

No dust or debris was stirred up in its passage. Therefore I theorized that zombies were relatively absent from this area. That did not necessarily mean that I was safe, though.

Maintenance workers had to have a way to get to the Oxygen Farm without being flattened by the train. Now that I was actually looking for it, the yellow ladder was obvious. It was recessed into the machine block behind me.

There would be no jumping up to the upper level. Not as damaged as I was, not with those huge spider-looking maintenance bots skittering across the machine block’s surface. As close together as the blocks were, there was little chance I could make it up without being struck even were I healthy.

The bots skittered over above me as I climbed, giving the practical reason why the ladder was sunk so deeply into the block I was on. The vibration through the ladder had started to numb my hands and feet by the time I was halfway up.

The thunderous shaking of the tall freight train grew again as I climbed, peaking and fading as it passed. On the next rung, my grip failed me and I slipped.

Only a frantic grab and wedging my forearm between the rungs saved me from drifting into the path of a maintenance spider that blurred by. The pain chose that moment to spike again and this time I could see bright sparks.

They weren’t just a trick of the eye. The wounds on my right arm were sparking, burning away the gauze and synthread stitches. The faint odor of burning hair and meat wafted as my HUD flickered once and died.

Then I stopped being able to see out of my right eye. I didn’t fall. Couldn’t, in microgravity. But straying into the path of unthinking machines could still get me killed.

The rest of the climb up to the catwalk seemed to take forever and was over in an instant at the same time. One minute, the rungs of the ladder were endless. Then there was a gap with the upper ladder not connected to the machine block. And then I was on the catwalk, feeling drained and barely able to stand.

I ate another meal bar to keep my grossly overpopulated colony happy. Or at least quiescent. My right arm still sparked occasionally, but did not hurt.

Well, no more than every other cell in my body hurt, anyway.

The view from up high was fascinating. I looked around in one eyed wonder at the long lines of machine blocks and the six legged maintenance bots that looked to be actually the size of spiders from up here. The tall freight train things had stopped moving at some point and now remained in the distance, close to the long vertical tube that appeared to hold the elevator shafts.

My destination was in that direction as well. Brightly lit power stations ringed the elevator tube. The catwalks stopped before reaching that point though, so I would have to climb back down once I got closer.

Various piles of... stuff lay here and there on the catwalks, some blocking the path forward. Not especially a problem in microgravity, though. There didn’t appear to be any zombies up here either. Infected being too uncoordinated to climb when there was gravity and probably too dumb to get out of the way of trains meant that they would likely be crushed to paste without the trains even slowing.

I kept turning my head as I made my way across the catwalk. Heights never had bothered me much. As much running around in microgravity I’d done lately, falling just wasn’t something that occurred to me. The sights were quite interesting to me as well.

I wondered what all the machine blocks were for. Some of them at least were part of the ventilation and gas mixing, others for water and plasma. Further away from the center I could see the blocks fall away and more commonly industrial looking infrastructure start to make an appearance.

Walker did a little bit of everything, before the collapse. Zero-g manufacturing, ore processing, refining, trade hub and support functions, goods transshipment and services all in one. There was even a bit of in-house food production, but nothing like the orbital farms further out system.

The shifting air currents from the trains that blurred around every so often necessitated sticking to the catwalk. There was no telling what program they ran on after seven years of neglect. The catwalk shuddered under my grip. It wasn’t as bad as the ladder, but every step seemed to sap just a bit more of my fading stamina.

The continued blindness in my right eye worried me. As did the shifting I could now feel in my body, motions no longer under my conscious control. I tried to remain calm. Unintentional commands could easily spell my death should my mental focus slip.

I realized that I’d reached the end of the catwalk with a start. The entire journey across my focus had been on making it one more foot further without losing control. I looked out beyond the descending ladder to the central hub.

Of course there was a horde. And of course it was no ordinary horde, but several giant zombies, a few with obvious implants as metallic arms and exoskeletons joined with withered flesh. There had to be hundreds of them packed together in a crowd in the open area around the elevator shafts.

Gravity appeared to be still working there. The massive power station complex towered over the horde, fat pipes snaking across gaps and plunging into the deck or rising through the ceiling. Small clouds of fog drifted here and there, alternately concealing and revealing zombies slumped in whatever passed for slumber for the infected.

There would be no making my way through that undetected.

Something down below me caught my eye. One of the trains below me was stopped. One of the cargo units it pulled held a vaguely familiar shape. It looked like one of the material handling units I’d seen on advertisements posted in the habs. The kind enticing young men and women to join the logistics team on Walker.

It wasn’t a space suit, but it might be close enough. It was about the size of the combat suit I’d piloted, but blocky and utilitarian where the combat suit looked rounded and sleekly lethal.

I was descending the ladder before I could talk myself out of it. The train would not remain there forever, judging by how often they had hurtled back and forth before.

An amber light on the train began to flash as soon as my foot hit the deck. I kicked off for the MHU, grabbing at it as I got close and missing. Then I crashed into the unit.

The train lurched into motion and started to pick up speed.