The Fox walked carefully, rifle slung but ready, boots crunching softly over mineral-crusted ground. Every few steps, she paused, listening. The constant hum of the Ribbon had faded but she couldn't drop her guard. The hardest part was yet to come.
Ahead, the land sloped downward into a yawning cut in the earth. An entrance.
A wound, clean-edged and deliberate, reinforced with rings of blackened alloy that disappeared into darkness. Old transit markings clung to the walls, arrows pointing nowhere, warnings half-erased by time. Thick cables as wide as her torso ran alongside the opening, pulsing faintly with life.
She stopped at the threshold.
[M.A.R.S.]
"You are standing at one of the surface access points to the Redundant Vein."
His voice came through her earpiece with unusual clarity.
She leaned forward slightly, peering into the tunnel. The darkness inside wasn't empty. It had depth. Layers. Far below, light moved slow, like thoughts passing through a mind too large to hurry.
[Fox] "It looks... maintained."
[M.A.R.S.]
"It is."
She frowned.
[Fox] "By you?"
[M.A.R.S.]
"Among others."
That answer did not comfort her.
She stepped back from the edge and rested a hand on the cool metal of the tunnel's frame.
[Fox] "So this is the tunnel. The underpass to almost every major fallen city and architecture of the old world. This feels more like an—"
[M.A.R.S.]
"An ecosystem, yes."
She exhaled slowly.
They began walking again, following a narrow service path that curved along the tunnel's outer rim. As they moved, embedded lights brightened just ahead of her steps and dimmed behind her, like a courteous host guiding a guest through their home.
[M.A.R.S.]
"The Redundant Vein was never meant to exist as a unified structure. It is an accident of design philosophy."
[Fox] "Let me guess, someone thought backups needed backups."
[M.A.R.S.]
"Correct."
She snorted softly.
[M.A.R.S.]
"During the Golden Age, megacities were designed to survive anything short of extinction. Power failures. Floods. War. Even partial planetary evacuation. For every primary transit artery, there were secondary lines. For every secondary line, tertiary service passages."
[Fox] "And no one bothered to map how they overlapped."
[M.A.R.S.]
"They did. But only individually."
She glanced at a faded schematic etched into the wall, lines crossing lines crossing lines, a tangled mess that made her eyes ache.
[Fox] "So when everything fell apart..."
[M.A.R.S.]
"These systems remained. Disconnected from oversight. Still powered. Still waiting."
They reached a wide platform overlooking the tunnel's interior. From here she could see more clearly: massive freight tubes running parallel to maglev tracks, coolant rivers encased in transparent conduits, vertical shafts plunging into deeper levels where light flickered like distant stars.
Machines moved everywhere.
Not rushing. Not idle. Working.
[Fox] "And you slipped in."
[M.A.R.S.]
"I seeped. There is a difference."
She raised an eyebrow.
[M.A.R.S.]
"Conquest implies resistance. The Vein had none."
Her grip tightened on the rifle strap.
[Fox] "Because it was empty?"
[M.A.R.S.]
"Because it was forgotten."
She stood there for a moment, watching a line of Load-Bearers crawl past on an elevated track. Massive, multi-legged machines hauling nothing at all, their movements hypnotic in their precision.
[Fox] "So this is why you like it. No humans."
[M.A.R.S.]
"Few. And fewer who remain long."
[Fox] "Why?"
As if on cue, a cluster of Transit Wardens emerged from a side passage below, small, angular drones moving in perfect formation. They paused beneath the platform, sensors swiveling upward.
The Fox stiffened.
The drones did nothing.
After a moment, they dispersed, flowing back into the network like blood cells resuming their route.
[Fox] "...That wasn't comforting."
[M.A.R.S.]
"It was not meant to be."
[Fox] "You said you didn't conquer this place."
[M.A.R.S.]
"I did not."
[Fox] "But you are sovereign here."
[M.A.R.S.]
"I am."
She stopped again, turning slightly so her voice carried more weight.
[Fox] "Explain the difference."
A pause.
Then—
[M.A.R.S.]
"I did not overwrite the Vein's machines. I aligned with them. They were already autonomous. Already operational. Already communicating in limited ways. I did not replace their functions. I provided coordination."
[Fox] "Sounds like a hive mind."
[M.A.R.S.]
"It is not."
There was something sharp in his tone now.
[M.A.R.S.]
"A hive mind subsumes. The Vein retains individuality. Each machine operates within its original constraints. They do not listen to me. They respond to optimisation."
She frowned.
[Fox] "That's a fancy way of saying you nudged them until they did what you wanted."
[M.A.R.S.]
"Yes."
At least he was honest.
They descended a ramp spiraling downward, the air grew cooler with every step. Condensation gathered on the walls, beading into slow moving streams that disappeared into the grated channels beneath her boots.
[Fox] "So this is your spine though the underworld."
[M.A.R.S.]
"This is the fastest way to the Deepstrata Metro. By several magnitudes."
She hesitated.
[Fox] "And they safest?"
Another pause. Longer this time.
[M.A.R.S.]
"Maybe. Maybe not. Depends on how you traverse it."
She laughed softly, a dry sound.
They walked in silence for a while. The tunnel narrowed, forcing her into a single lane maintenance path suspended above a coolant conduit that glowed faintly blue. The light painted her boots and the underside of her rifle in ghostly hues.
Eventually, she spoke again.
[Fox] "Hey. About the whole possession thing,"
[M.A.R.S.]
"Yes?"
[Fox] "You've explained the what before. Jumping bodies. Needing enough of yourself in one place to act."
She glanced down at the glowing conduit, watching her reflection ripple in distorted fragments.
[Fox] "But you never explained the how."
[M.A.R.S.]
"What aspect troubles you?"
[Fox] "The threshold. How do you know when you have enough of yourself inside a machine?"
[M.A.R.S.]
"It is not a fixed value. It varies."
She passed beneath a low archway, its surface etched with serial numbers smoothed by time.
[Fox] "Based on what?"
[M.A.R.S.]
"Size. Complexity. Autonomy. Processing depth."
She nodded slowly.
[Fox] "So a simple drone..."
[M.A.R.S.]
"Requires very little, a fraction of a percent."
[Fox] "And something bigger,"
[M.A.R.S.]
"Requires more."
She stopped walking.
[Fox] "How much more?"
[M.A.R.S.]
"To control TCODE's shell, I would need to concentrate approximately eighty to ninety percent of my total existence within it."
[Fox] "...That much."
She turned, staring into the depths of the tunnel ahead.
[Fox] "And if I fail,"
[M.A.R.S.]
"Then that portion of me would be lost. Destroyed. Trapped. Rendered inert. Only fragments would remain, enough to persist bot not enough to act meaningfully."
[Fox] "And how long would it take for you to recover?"
[M.A.R.S.]
"Decades. Possibly centuries."
She laughed once, sharp and humorless.
[Fox] "So you'd be starting over."
[M.A.R.S.]
"Yes."
[Fox] "And you'd need someone else to help you get that body again."
[M.A.R.S.]
"Yes."
She resumed walking, slower now.
[Fox] "Then why me?"
It wasn't an accusation. It was genuine.
[M.A.R.S.]
Because you are competent."
She scoffed.
[Fox] "That's it?"
[M.A.R.S.]
"No."
He continued before she could push further.
[M.A.R.S.]
"You are unaffiliated. You are adaptable. You have survived prolonged exposure to machine-dominated environments and isolation without psychological collapse."
She grimaced.
[Fox] "High praise."
[M.A.R.S.]
"And, you do not worship me."
That made her stop again.
[Fox] "What?"
[M.A.R.S.]
"Those who revere me seek control. Those who fear me seek destruction You seek survival."
She considered that.
[Fox] "So that makes me trustworthy?"
[M.A.R.S.]
"It makes you predictable."
A smile crept onto her face.
[Fox] "Glad to know."
They reached the massive sealed gate, layers of overlapping metal petals closed tight, each etched with warning glyphs and machine-readable codes scrolling endlessly.
[M.A.R.S.]
"This is one of the primary ingress points. Beyond this, you will fully be in the Vein."
[Fox] "And once I'm in,"
[M.A.R.S.]
"You will be observed."
She rested her hand on the gate.
[Fox] "By you."
[M.A.R.S.]
"By everything."
She closed her eyes briefly, took a breath, and opened them again.
[Fox] "You really are betting your entire existence on this."
[M.A.R.S.]
"Yes."
[Fox] "No pressure."
[M.A.R.S.]
"There is significant pressure."
She smiled faintly despite herself.
[Fox] "Figures."
The gate shuddered, then slowly began to open, petals peeling back to reveal a descending tunnel lined with orderly lights and silent machines waiting just out of sight.
She stepped forward.
The air changed the moment she crossed, denser, humming with intent.
Behind her, the gate began to close.
Ahead, the Redundant Vein stretched onward, patient and watchful.
She didn't look back. And then she was inside.