Marcus moved south on Day 10, not to the Ashborn but to a better position. He'd found the room on Day 5, a sealed space with an intact door that swung on greased hinges, clean air whispering through a ceiling grate linked to something functional above. Close to the gallery food source and the corridors south toward Ashborn territory. The door had a bolt that slid home with a solid clunk. The Lens rated the walls at eighty-nine percent integrity, the highest reading he'd pulled down here. The room smelled of machine oil and cold metal, the ghost of its purpose clinging to the ferrocrete.
He moved his few possessions: the metal cup, the last protein ration wrapped in cloth, the filtration tablet Maren had traded him. He stripped a fresh coil of copper wire from a conduit near the new shelter, the Lens confirming the pre-Noctis alloy he'd traded before. The whole lot fit in one hand, ten days alive compressed into a fistful of scrap and borrowed chemistry. Everything he had earned in this world weighed less than a kilogram.
The move took two hours, most of it spent checking routes and scanning each junction with the Lens for signs of traffic. Scuff marks on the grating. Shifts in the dust that coated everything down here like slow geology. Thermal ghosts of bodies that had passed through in the last few hours. He logged each trace, building a picture of who walked these corridors and when. The patterns told a story: two regulars on a north-south loop, one heavier set who favored the east branch, and gaps in the traffic that matched the timing of Reaver patrols three levels up. Useful data. The kind of data the Ashborn would pay for.
Then he sat on the maintenance room's floor, back against the cold wall, the Lens painting the dark room in its wireframe blue. Above, a pipe ticked with the rhythmic pulse of heated metal, the only clock the underhive offered.
He did what he'd been trained to do since his first day as a software engineer.
He built a model.
The underhive, as he now mapped it, was a distributed architecture with no central coordinator.
He laid it out the way he'd diagram a microservices platform at work, breaking each component into what it consumed, what it produced, and how it failed. The exercise was calming. Abstraction turned a lethal environment into a set of dependencies he could study and, given time, reshape.
The physical infrastructure was the hardware layer: tunnels stretching for kilometers in every direction, hab-blocks stacked and collapsed and rebuilt over centuries. Water mains had been cracked, rerouted, and patched until the plumbing was indistinguishable from the modifications. Ventilation ducts wheezed with grime, pushing air that tasted of rust and recycled breath. Power conduits arced and sparked in the walls like the nerves of some dying animal. All of it wearing down at different rates, maintained where someone held the ground and left to rot where no one did.
The gangs were the services layer. The Ashborn ran governance and security in their quarter. The Crimson Reavers ran conquest and consumption in the Red Sprawl. The Ironworkers kept infrastructure running where the effort was worth the cost. The Pale Court brokered information through channels Marcus could not yet trace. Each faction depended on the others in ways no one admitted, all chasing scarce resources with no one managing the traffic between them. No one coordinating the whole. No one watching the architecture's health except, now, Marcus himself.
The resources were the constraints: water, food, breathable air, weapons, ammo, skilled labor, information. Every transaction in the underhive was a negotiation over these limited inputs, a zero-sum game played on a substrate of corroded metal and fungal protein.
Maren's circuit trading was a message queue, carrying small bundles of value between nodes that could not reach each other. Her routes traced paths of least resistance through territorial borders that shifted like fault lines. The scavengers were the garbage collectors, pulling useful material from dead infrastructure and feeding it back into the active economy, keeping the whole construct from choking on its own waste.
And Marcus, with his Analysis Lens and a decade of observability engineering, was the monitoring dashboard nobody had asked for. Structural integrity, air toxicity, nutritional content, threat scores for every person in range drawn from body language and weapon condition. He could read the underhive's metrics in real time, the way he'd once read Grafana panels at his desk when something started throwing errors at 3 AM.
The question was what to do with that visibility.
He spent the morning mapping everything onto this model, refining the edges, filling in the gaps where he could and flagging them where he couldn't. Ashborn territory was the governance node: stable, resource-positive, accepting new members in exchange for labor. Their water recycler was the dependency that everything else turned on. Reaver territory was the aggressive node, resource-negative and dependent on raiding to stay fed. Consumption outpacing production like a service with a memory leak that would crash no matter how much hardware you threw at it.
The scavenger zones were the unmanaged commons: no coordination, high overlap, low output. A hundred individuals duplicating each other's work because no one had built the framework that would let them specialize. The Sump was the failure boundary, the level below which the whole model degraded into toxicity and death. The bottom of the stack trace.
The model was incomplete. He had no data on the Ironworkers beyond scraps from overheard talk. Nothing on the Pale Court beyond inference and rumor. Nothing on Chaos, xenos activity, or how far the Imperium reached into the underhive. Each gap was a node with unknown edges. A dependency he could not resolve until he had more data.
The model was enough to plan with, because the point of a model was never to be complete. The point was to be useful: surface the dependencies that mattered, find the variables that could be changed. Marcus had shipped production software built on rougher models than this one.
In the afternoon, Marcus began testing the Precursor framework's growth mechanics with controlled experiments.
He stretched his legs in the corridor outside his shelter, the grating cold beneath his feet, and rolled his shoulders until the joints cracked. A dry sound from a body still adjusting to demands it had never been built for. He'd been forming hypotheses since Day 2: the framework rewarded novel actions, with diminishing returns for repetition. Now, with a secure base and enough food to sustain experimentation, he ran controlled trials with the patience of an engineer benchmarking an unfamiliar platform.
First: repetition. He walked a corridor ten times, focusing the Analysis Lens on an identical wall section with each pass. The Lens returned identical data on every circuit: structural reading, material makeup, corrosion score. The exact readout repeating without variation. No new detail unlocked, no skill gain. Navigation refused to advance, because doing a thing twice was not learning.
Second: escalation. He climbed a beam to the ceiling of the corridor, pulling himself up hand over hand with arms that shook from the effort. His STR 4 body protested every centimeter, sweat stinging his eyes, grip slipping twice on corroded metal. But the Lens mapped ceiling features hidden from floor level: cable runs, pipe junctions, heat traces from active conduits, the outline of a sealed hatch leading to the level above.
Navigation ticked up. New data, new angle, new gain. The framework rewarded the effort of seeing from a place no one bothered to reach. From up here, the corridor looked different. The floor grating showed wear patterns invisible at ground level, paths beaten smooth by years of foot traffic, and one section where the metal had been cut and welded back with a different alloy. Someone had hidden something under that grating, once. The Lens flagged the weld as recent, less than a year old. Marcus filed it away.
He lowered himself one handhold at a time, arms shaking, and dropped the last meter onto the grating with a clang that echoed through the corridor. He froze, listening for any response from the darkness. None came. The corridor held its breath, and so did he.
His forearms trembled with the fine tremor of tissue pushed past its limit.
The notification was worth the price.
Third: combination. He moved through a corridor he had not walked before, staying quiet while running the Lens on target after target. Wall to ceiling to floor to the junction ahead. The layered task was harder than either piece alone. His brain struggled to hold stealth focus while processing Lens data, each demand crowding the other out. Twice he lost the thread of one to chase the other, his footstep landing too hard while he parsed a corrosion reading, his scan going blank while he corrected his weight on a creaking grate.
Stealth, however, advanced. The framework treated the combined work as something new, distinct from either skill used alone.
The pattern was clear. The Precursor framework was an engine calibrated for what software engineers called the "learning zone": the gap between what you could do with ease and what you could not do at all. Too easy meant no growth. Too hard meant failure, and failure without a win was noise, not signal. The sweet spot was novelty within reach, the edge of competence pushed outward one step at a time.
"Home ground," Marcus murmured to himself, and the words bounced back from the ferrocrete, thin and strange in the corridor's stillness.
His whole career had been built on this principle. His reviews at Lattice Systems praised his drive to push into unfamiliar problem spaces and come back with working solutions. He grasped feedback-driven growth the way a musician grasped scales, at the level of reflex.
[Stealth: Novice 2 -> Novice 3. Navigation: Novice 3 -> Novice 4. Foraging: Novice 4 -> Novice 5.]
[Attribute shift detected: INT 8 -> 9. Trigger: sustained analytical engagement over multiple sessions. Note: first attribute improvement recorded.]
INT 9.
His first attribute gain.
Something unlocked in his chest that had nothing to do with the number and everything to do with what it confirmed. The framework tracked not only skills but the attributes that powered them. Sustained intellectual work moved the needle. Attributes grew from behavior, shaped by what he did, only slower and with a higher bar for what counted.
The body was still weak, sitting at STR 4 and AGI 6, though the Lens noted gains starting from climbing and moving over rough ground. END 5 crept toward 6 as sustained activity pushed the cardiovascular baseline upward. The forearm scar from his first days had faded to a white line the Lens no longer flagged.
The mind, though, his best tool, was growing. INT 9 meant the Lens would sharpen: outputs a touch more detailed, processing a touch faster, threat reads tighter by increments that would compound over time. Every skill that scaled with INT would ride the rising tide.
Marcus let himself smile. First time this face had shaped the expression, and the muscles resisted, unfamiliar, as if the body he wore had not been built for it. The boy who had lived here before him had not smiled often. Marcus could not blame him. But the smile stayed, and it was his.
He spent the evening building the cover story he would need for the Ashborn.
The Ashborn, according to Maren, took workers. They would ask where he came from, what he could do, why he was alone. His answers needed to be consistent, believable, and unremarkable. A story that would satisfy a checkpoint guard without triggering scrutiny from anyone with real authority. He built the cover like a test fixture: robust enough for the expected inputs, flexible enough to accommodate variations, simple enough that he would not trip over his own complexity under pressure.
Origin: The Warrens. The lower Warrens, near the underhive boundary, a zone where people sometimes fell through. By accident, or pushed down by the hive's pressure, the desperate shoved against the doomed. Maren had flagged his accent as unusual. He would explain it as "upper Warren dialect," close enough to Low Gothic that the differences read as class instead of alien origin.
He practiced the clipped underhive speech: dropping articles, cutting vowels short, swallowing the ends of words the way every underhiver he'd overheard spoke. The language itself worn down by the environment the way ferrocrete walls were worn down by the constant dripping of recycled water.
"Family's gone," he said to the empty room, testing the cadence. "Came down three months back. Scav work, mostly. Good eyes."
He tried it again with his jaw looser, swallowing the consonants the way Maren did. "Came down after the last purge. Lost everyone. Been running solo since."
The words tasted like someone else's mouth, but each repetition pulled them a fraction closer to his own.
Skills: Scavenger. Good eyes, good memory, quiet on his feet. He could spot good materials, read wear patterns, find safe routes through bad corridors. All true, all easy to credit to talent and hard living instead of an alien framework feeding data to his visual cortex.
Why alone: Family dead. Common enough in the underhive to require no further explanation, and painful enough that decent people would not press for details. The lie sat in his chest like a stone, because in Portland, Oregon, in a world he could not reach, his mother might be grieving a son who would not call on Sunday again.
What he offered: Intel. Reaver patrol data, route maps, structural assessments of the corridors between the Ashborn border and Reaver territory. Information the Ashborn's scouts would find valuable, delivered by a newcomer who wanted to earn his place, not beg for one.
He rehearsed the story until it stopped sounding memorized and started living in his jaw and his breathing. A practiced lie became the same as truth when you stopped thinking of it as deception and started thinking of it as another version of yourself.
He drilled the accent, repeating Maren's phrases and the fragments of speech he'd caught from the scavengers in the junction room, and kept at it until the Lens rated his output as
[Consistent with lower Warren / upper underhive dialect. Anomaly detection probability: LOW.]
Good enough.
Then he sat in his maintenance room, the dim blue wireframe of the Lens casting faint shapes on the walls, and listened to the vents fill the silence with their mechanical breathing. The air tasted clean here, cleaner than his last three shelters. A small mercy he was learning not to waste.
What was he doing? Walking into a community of fighters and civilians and presenting himself as something he was not. A Warren refugee who happened to have sharp eyes and good intel. Not a dead software engineer from another reality carrying an alien construct that could read walls and people at a glance. Not a man with tabletop knowledge about this universe that no one on this planet could possess, gleaned from game books and wiki pages and late-night arguments with Tyler ten thousand light-years away.
The lie was needed. The alternative was discovery, and discovery was death, not his alone but the death of anyone who had helped him, anyone the Inquisition or the Mechanicus decided had been tainted by contact with xenos tech.
The lie was also a kind of original sin. Every bond he built would rest on a false floor. Every trust he earned would carry the stain of the secret, the construct painting data across his sight while he shook hands and made promises and pretended to read the world the way everyone else did.
This was the price. Not the framework, which was a tool. Not the underhive, which was a place. The price was that Marcus would never be honest with anyone he met. Every friendship would carry a gap shaped like the truth he could not tell. Every alliance would rest on a secret that could destroy everything the alliance had built. And every time someone trusted him, they would be trusting a version of Marcus Webb with the most important variable hidden behind a wall no one else could read.
He had built access control layers in his previous life, designed them to protect data from unauthorized eyes. He had never imagined the data would be his own existence, or that the unauthorized users would be every person he would ever meet.
The Quest Log sat in his peripheral vision, its text steady now. The stuttering of the early days had settled into something that resembled consistency if not reliability. Three priorities, battered and half-translated, forming a roadmap he had not asked for but could not refuse.
Priority 1: Survive. Status: Stabilized. Priority 2: Establish sustainable resource access. Status: In progress. Priority 3: Identify local power structures. Status: Mapped and approaching.
Eleven days since he woke in the dark. Eleven days since Marcus Webb died on a street in Seattle and opened his eyes in strange skin at the bottom of a universe that killed the careless and the unlucky with equal speed. His body was stronger, his mind sharper, and his map had names, borders, and the outline of a plan. He had a cover story the Lens rated as plausible and a pocket of copper wire that passed for money among people who weighed wealth in grams.
He closed his eyes and let the wireframe overlay hold on the inside of his eyelids, the underhive's pulse vibrating through the ferrocrete at his back. The pipe above ticked its slow rhythm. Far off, a vent fan cycled down with a groan that sounded alive, the hive settling into whatever passed for night in a place that had never met a sun.
Eleven days from dead man to functional. The Ashfall Quarter waited south, and Marcus had one chance to make a first impression on people who decided whether strangers ate or bled. He intended to make it count, because the underhive did not offer second chances to anyone.
------------------------
To read 20 advanced chapters you can visit my Ko-fi:"Ko-fi.com/theprosecutor''