Marcus started with the wall. Four hours until the body gave out, and he intended to spend every one of them learning what the alien machine in his head could do.
He pressed his left hand flat against the corroded metal and focused the way he had during outages, letting his attention narrow to a single point. The overlay fired at once, text sharp and clean against the dark, as if the gloom around him were a design choice, not a hazard.
[ANALYSIS: Ferrocrete composite, Pattern Unknown. Age: est. 3,800 standard years. Structural integrity: 41%. Corrosion: advanced (chemical + biological). Load-bearing status: COMPROMISED — micro-fractures detected in reinforcement lattice. Advisory: avoid sustained pressure on this surface.]
He lifted his hand and the text faded to a ghost of itself, dimmed but persistent in his peripheral vision like a minimized window. He redirected his attention to the grating under his feet.
[ANALYSIS: Industrial decking, ferrosteel alloy. Age: est. 2,100 standard years (newer installation, maintenance-era). Load capacity: 73% of rated spec. Corrosion: moderate. Note: subsurface void detected 2.4 meters below. Structural risk: LOW (current load).]
He directed his attention to the open air in the tunnel ahead, and the Lens offered nothing useful: temperature, humidity, particulate density. A boundary condition. He filed it the way he would have filed a null response from an API call. A limit that told him what the tool could not do, which was as useful as what it could.
He turned his own hand over, spreading the fingers that were thinner than they should have been, the knuckles sharp under skin that had the translucent quality of prolonged malnutrition.
[VITAL STATISTICS — UPDATE]
Status: CRITICAL
Hydration: 29% (declining — 2% since last reading)
Nutrition: 11% (STARVATION THRESHOLD)
Core Temperature: Elevated (low-grade immune response, 18.7°C ambient)
Estimated time to incapacitation: 3.2 hours (hydration-limited)
The numbers had gotten worse. Walking burned what his body did not have to spend. The System tracked the cost with cold detail, each tenth of a point ticking down like a timer on a process that would end when it hit zero. Three point two hours until the body quit on him. He pushed off the surface and kept moving toward the sound of water, his bare feet registering the shift from gritty ferrocrete to rusted grating as the tunnel angled downward. The air grew denser, carrying a mineral tang that cut through the baseline stench of stagnant decay. Somewhere ahead the dripping sound resolved into a thin, continuous trickle that echoed off surfaces he could not yet distinguish in the dark.
The Lens was event-driven, not polling. Hard focus on a target pulled detailed output; a glance gave only surface-level data. He tested this by scanning the same section twice, first with a casual sweep, then with deliberate concentration. The sweep returned material type and a rough age estimate. The focused pass pulled the full readout, down to micro-fractures and load ratings. Intent scaled the detail, the same way adjusting log levels on a debug framework exposed deeper traces.
Solid objects gave rich reads while air returned next to nothing. His own body produced live vital stats that tightened his stomach with every drop. The Skill Tracker, called up with a thought, sat empty:
[No skills registered. Awaiting activity data.]
The System learned from what he did, not what he knew. Not a screen where you picked stats from a menu, but a feedback engine that tracked skills as they showed up in action. A man who had spent six years building observability platforms for distributed software could recognize the architecture, even wrapped in alien skin.
The sound of water grew louder as the tunnel widened into a junction where three corridors met. The ceiling rose past arm's reach, and a faint amber glow leaked through gaps in the plating above, throwing long shadows across standing liquid. Most of it was poison, the Lens confirming it without being asked: chemical runoff from above, heavy metals, industrial solvents that had dripped through the hive's guts for centuries.
In the far corner, though, a pipe as thick as his thigh jutted from the ferrocrete at an angle that spoke of ancient settling, water dripped into a shallow basin. The flow was thin, a thread of liquid catching the amber light, but the basin held maybe eight liters.
[ANALYSIS: Water. Contamination: LOW (trace mineral content within safe consumption parameters). Source: cracked primary water main, pre-settlement era. Temperature: 14°C. Volume: ~8.2 liters. Replenishment rate: ~0.3 liters/hour. Advisory: safe for consumption. Boiling recommended but not required at current contamination levels.]
Safe for consumption, and Marcus's knees buckled half an inch before he caught himself against the ferrocrete. Something loosened in his chest that had been tight so long he'd stopped registering it. He crossed to the basin and knelt, cupping water in both hands, and drank.
He drank in careful sips. Through the fog of desperation, first-aid training from his company's annual safety course surfaced: if dehydrated, small sips. Gulping could trigger vomiting, and vomiting meant losing more fluid than he'd gained. So he sipped, let the water sit in his mouth, swallowed, and waited. Sipped again. The water tasted of minerals and age, metallic on the tongue, the best thing he had tasted in either of his lives.
[Hydration: 29% -> 32%. Status: CRITICAL (improving). Advisory: sustained intake over the next 2-4 hours recommended. Avoid overconsumption.]
He sat back on his heels and kept drinking, small mouthfuls spaced by the time it took to count to thirty. The first-aid training had been drilled into him during a company safety course he had never expected to use for anything real. It was real now. The number climbed, thirty-four percent, then thirty-six, each sip a data point in a recovery curve. The time-to-death counter stretched longer, the death sentence softening into something dire instead of terminal. Then a new line appeared, different from the vital stats. It carried a weight the health readouts hadn't.
[SKILL UNLOCKED: Foraging — Novice (1)]
[Activity recognized: identification and acquisition of safe consumable resources in hostile environment.]
[Skill Tracker updated.]
His first skill. Not picked from a menu or given for reaching a threshold, but earned through the act of finding safe water in a place that wanted him dead. The System had watched him find water, recognized the pattern, and created a category for it.
A learning model trained on a sample size of one, sorting skills from what he did. The training data was his life. Every action fed back into the machine. For someone who had spent years building this kind of feedback loop in software, the System was the first thing since waking that made the world feel like a problem he could work.
He didn't grasp the System's full design, its limits, or why it had woken for him. But he understood feedback loops, and the fastest way to map a tool with no manual was to press every button and watch what came back.
He drank until the reading held steady at thirty-nine percent and the System's urgency downgraded to caution. A metal cup wedged between two slabs of ferrocrete nearby went into his waistband. The Lens tagged its alloy and age without being asked, one more line in a growing index of the world.
Nutrition still held at eleven percent, a slower crisis than thirst and every bit as deadly. Water alone would not solve it. Still, water bought him time, and time was the one currency that let him spend all the others.
The hab-block lay thirty meters from the water source, through a stretch of corridor where the ceiling sagged close enough to brush his hair. The Lens painted stress fractures across every joint in urgent amber. Safe to traverse, not to live in. Marcus moved through with care. Beyond the choke point, the space opened into something that had once been lived in: small rooms branching off a central hall, thick partitions with doorways narrow enough to block. The air smelled different here, dryer, carrying less of the reek that filled the main tunnels. The temperature dropped two degrees as the stone around him drank whatever heat his body could spare. Marcus checked each room the way he used to audit server rooms: slow, thorough, noting every flaw and comparing it against the mental checklist of what survival required.
[STRUCTURAL ANALYSIS: Room 1 of 4. Ceiling integrity: 67%. Wall integrity: 71-84% (variable). Single entry point (width: 0.9m). No secondary egress. Subsurface: stable (bedrock contact at 1.2m). Assessment: DEFENSIBLE. Habitability: MARGINAL (no water, no ventilation beyond corridor airflow, no light source).]
The third room was best. Two sides backed against solid ferrocrete the Lens rated at eighty-four percent, with the entry point angled so anyone inside got a moment's warning before a visitor could see in. Ceiling intact, no cracks, no water damage, the reinforcement having survived whatever catastrophe collapsed the outer sections.
Marcus sat down with his back against the far surface and let himself breathe. Stopping revealed the cost of the walk: a tremor in his thighs, a grey haze at the edges of his vision that had nothing to do with the Lens.
The hab-block was older than the grating in the tunnels, older than the water pipe, old enough that the things left behind had turned to dust and guesswork. A metal cup, which he'd taken, and a sleeping pad worn to fiber, the synthetic weave reduced to something like coarse gauze. Scratches scored into one surface that might have been a child's drawing, a rough map, or nothing at all. Marks left by people who had lived and died in rooms like this one, miles below sunlight, in a structure that would outlast their names by ages. Marcus ran his fingers across the scratches and the Lens tried to parse them, returning only
[Marking: indeterminate. Pattern recognition: insufficient data.]
, which was honest if unhelpful.
The Lens dated the space to 3,800 standard years. Four millennia, and the ferrocrete still held. The startup he'd worked at had been three years old and falling apart. This room had been bearing weight longer than most civilizations on Earth had lasted.
He ran his hand along the base where ferrocrete met floor, and his fingers found a seam. Not a construction joint. Something different, a place where the builders had poured around a pre-existing structure. He focused the Lens.
The response flickered. The text stuttered and reformed in a way he had not seen from the Lens before, as though the machine were struggling to read what it had found.
[ANALYSIS: Material composition — ]
For a split second, the readout broke apart into sharp, angular marks from the System's boot sequence, the same alien script that had scrolled across his vision when the machine first woke. The glyphs held for half a breath before the Lens pulled its standard text back into place.
[Material: UNKNOWN. Age: ERROR — value exceeds calibrated reference frame. Composition: PARTIAL MATCH (ferrous substrate, crystalline inclusions, molecular structure non-standard). Classification: Pre-Imperial archaeological anomaly. Insufficient data for further analysis.]
Marcus pulled his hand back. The material ran darker than the ferrocrete around it, almost black, with a surface smoother than anything else he'd touched in the underhive. It sat in the foundation like rebar, except rebar didn't make alien machines glitch into dead languages.
Something older than the Imperium was embedded in this place, buried in stone that had been ancient when the first settlers arrived.
No actionable data, no clear next step, and no obvious connection to the immediate problem of staying alive for the next twelve hours. A good engineer, though, never discarded anomalous data because the current model couldn't explain it. He flagged it, time-stamped it in the mental filing system that had once tracked production incidents and now tracked an alien world. Set it aside until the pattern showed itself.
With water found and shelter secured, he turned to the problem he'd been circling since the System's location data had blown apart everything he thought he understood about where he was.
He sat cross-legged in the third room, the Lens painting the darkness in faint wireframe, and began working through his inventory of facts.
The System was not from the tabletop game, and the certainty of that conclusion carried both relief and a cold new species of dread.
He'd run the comparison point by point, matching the two systems against each other like codebases that might share underlying architecture. The game used Weapon Skill, Ballistic Skill, Strength, Toughness, Wounds, Initiative, Attacks, Leadership. The System used STR, AGI, END, PER, INT, WIL, CHA. Different attribute models, different scaling conventions, no recognizable overlap. The tabletop had no equivalent of the Analysis Lens. The RPG spinoffs used skill systems, but nothing that resembled the System's activity-driven feedback loop.
The errors told the real story. A system native to this setting, whether Imperial, xenos, or Chaos, would not produce error messages in a language that predated the Imperium itself. It would not reference a consciousness "out of phase" or classify its host as a displaced entity of external origin. It would not designate itself an Uplift Construct, a classification that belonged to no faction, no recognized technology, no historical period that Marcus's tabletop knowledge covered.
Something else, ancient beyond reckoning. Built by a civilization that predated the Imperium by an interval the System could not quantify without erroring out.
Imperial technology was sanctioned by the Adeptus Mechanicus, maintained through ritual repetition and sacred STC templates. Xenos technology was forbidden but at least recognizable, something the Ordo Xenos hunted and destroyed. Tech from before recorded history was something else. A maker so old its own tool could not read the language sat in Imperial doctrine somewhere between "heresy" and "burn the planet from orbit."
The Inquisition would not ask polite questions. They would ask exacting ones, with the subject strapped to a device that made answers difficult and survival unlikely.
Marcus closed his eyes. The Lens stayed, a faint blue grid on the backs of his eyelids, beginning to merge with his vision instead of sitting on top of it. His right thigh buzzed with the phantom pulse of a phone that didn't exist, had never been in this body's pocket. A ghost signal from a pair of jeans in a Seattle apartment that Marcus Webb would never walk into again. He clenched his fist and held it until the sensation passed.
One problem at a time. The Quest Log had been generating since activation, stuttering through partial objectives the way a deployment script failed on dependency resolution. The current state was half-broken.
[QUEST LOG — STATUS: GENERATING]
Priority 1: SURVIVE (ongoing)
Subgoal: Maintain hydration above critical threshold [IN PROGRESS]
Subgoal: Acquire caloric intake within 8 hours [PENDING]
Subgoal: Secure defensible shelter [COMPLETE]
Priority 2: Establish sustainable resource access [TRANSLATING...]
[Partial: identify reliable food sources, water sources, trade goods]
Priority 3: [ERROR — ᚦ̷ᛇ̶ᚱ̵] ...identify local power structures [CONFIDENCE: LOW]
[Partial: map territorial boundaries, assess faction capabilities, determine political hierarchy]
Priority 3 stopped him cold. Identify local power structures, map territorial borders, assess faction strength. The Quest Log, glitchy and half-translated as it was, had built objectives that reached past personal survival into something that read like the first steps of an intelligence brief. The kind of structured reconnaissance a military analyst would produce before deploying assets into unfamiliar territory.
An onboarding sequence, and not for a tool built to keep one person breathing. For something that expected its user to grow, the progression implicit in the objective hierarchy: survive first, then establish resource access, then map the environment's power dynamics and political topology. The logic assumed growth, each layer of skill serving as the base for the next, which meant the System had been built by something that planned for scaling and not for keeping one person alive in the dark.
Tier 1, Survivor, not "warrior" or "adventurer" or any character class a game would assign. A label that implied Tier 2 and beyond, each one asking more from its host than not dying. The Quest Log was already building the list for whatever that next step demanded.
Marcus leaned his head back against the ferrocrete and stared at the Lens's pale geometry. The vital stats floated at the edge of his vision like a dashboard for a server running at fifteen percent. Every metric red. Every alarm muted, because the noise would not help.
He had a foothold, though. Water he could return to. Shelter that would hold. A System that, for all its damage, gave him information, and information was the only resource that mattered when he had nothing else.
He pulled up the Skill Tracker. One entry: Foraging, Novice 1. A single data point. The question was not what the System could do for him, but what he could do that it would recognize, catalogue, and optimize.
He needed food. The Lens had flagged a fungal growth during the structural survey: low caloric value, non-toxic, edible if unappetizing. He crossed to where it clung to the ferrocrete in blue-green patches, scraped a portion free with his thumbnail, and ate it.
It tasted like wet chalk with a bitter finish, and his stomach clenched around it with a desperation that rendered the flavor irrelevant.
[Foraging: Novice 1 -> Novice 2. Activity recognized: identification and consumption of non-standard food source in resource-scarce environment.]
Novice 2. He ate more, pacing each bite, giving his stomach time to remember what food was. When the nausea passed and the cramping eased, he leaned against the wall with the taste of chalk in his mouth and the first faint sense of a body being fueled instead of endured.
[Nutrition: 11% -> 13%. Status: CRITICAL. Advisory: caloric intake insufficient for recovery. Seek higher-density food sources.]
Thirteen percent, which was still dying, but dying at a crawl instead of a sprint, and in the underhive that qualified as good news.
Tomorrow he would start mapping. Not as a fugitive looking for the next meal, but as an engineer studying a system, identifying inputs and outputs, dependencies and failure modes, pressure points and opportunities. The Lens would give him data no one else could access. His ability to interpret that data, to trace the dependency chain from cause to effect, was the one advantage that no amount of hunger or terror could strip away. He had been good at this on Earth, good enough that companies paid him well to find the stress fractures in their architectures before those fractures cascaded into failures. The setup here was different, built from steel and suffering instead of code and servers. But the method was the same: observe, model, test, iterate, and never trust a system because it looked like it worked.
Water dripped in the corridor outside, counting seconds he had no other way to track. The Precursor error text flickered at the edge of his vision, the same script that had flared when the Lens touched the dark material in the floor. Marcus filed it next to the Quest Log's third priority. Loose threads, both of them, in a pattern he could not yet trace but was starting to suspect had a shape.
Somewhere above him, past kilometers of steel and ferrocrete, tens of billions lived and died under an empire that would kill him for what he carried. Below, something older than that empire slept in the bedrock. The machine in his head kept running its slow, damaged work, building a task list for a user whose first day was not yet over.
Marcus closed his eyes. The Lens painted its quiet grid on the backs of his eyelids, and for the first time since waking in this body the blue lines did not feel alien. They felt like the start of a map.
He slept, and the System watched, its overlay a faint blue pulse on the backs of his eyelids that dimmed as his breathing slowed and his body gave itself over to the first rest it had known since the transfer. Priority 3 went on building in the dark, adding tasks for a host who had not yet lived long enough to try them.
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