161: Chapter 161 Returning to the Northeast (73)

At six in the morning, the outer gate of the Outpost slowly opened.

The G-Explorer-C folded its six legs and crouched on the towing rack, riding along with the modified motorcycle into the red Wasteland that he had traversed back and forth ten times.

The first forty kilometers had long been marked down to the millimeter; the risk points of compacted soil, rubble slopes, and dry gullies no longer required inch-by-inch exploration on foot.

Dropping R-01 at the fifty-five-kilometer mark and fine-tuning the landing point of R-02 at sixty-four kilometers to avoid the ventifact ridge, the deployment parameters of the two relays were already thoroughly memorized, the signal-to-noise ratio passed verification on the first try, and there were no extra pauses throughout the entire journey.

R-03 to R-06 were not deployed in advance; they were breadcrumb relays inside the collapse zone, dropped on demand only after the G-Explorer-C left the safety boundary marker.

The more fixed relays there were, the higher the recovery cost, and the easier it was to lock down the retreat route.

At the seventy-kilometer milestone, Jiang Lin pressed down on the handlebars and came to a steady stop.

Raising his eyes to look, the outer edge of the Northeast Seventy-Three Abnormal Collapse Zone had spread out at the end of his vision.

In the fifteenth year of the previous cycle, when he first stood here, what he saw was a grayish-white dead zone.

Rubble, collapse, subsidence—a ruin showing no discernible pattern whatsoever.

The questions back then were very simple: Were there any man-made objects here, what was the PMCU-17, and did a computing array exist underground?

At this moment, standing in the exact same spot, what he saw was something else entirely.

The drone lifted into the air, and the view rose.

The thermal infrared lens swept across the grayish-white collapse zone, and on the screen, the surface thermal distribution was rendered into a grayscale map.

The ordinary rubble slopes were uniformly cold, and the bottom of the wind-eroded gullies was slightly darker.

These were all background noise of the Wasteland; he swept his gaze over them and filtered them out directly.

What he needed to find was the line that should not exist.

On the northeastern edge, an extremely weak linear residual cut diagonally across the collapse zone.

If it were the Jiang Lin of fifteen years ago, this line would only have been classified under surface material differences, not even worth writing a note for.

But the Jiang Lin of today held in his hands the cooling interface orientation data of the PMCU-17, the geometric model of the collapse shear direction, and the outer-ring thermal management network hypotheses run countless times by the MPS-Agent α.

With these three things stacked together, this line was no longer noise, but the projection of a cooling trunk line.

Jiang Lin re-superimposed the drone footage with the cooling interface orientation of the PMCU-17.

The angular difference was thirteen degrees.

Thirteen degrees was enough to refute a conjecture on a precision engineering drawing, but in a Wasteland site that had experienced seismic shear, stratigraphic displacement, and landslide compaction, this deviation was well within the allowable range.

Then he dropped the first marker on the map.

[Candidate Outer Ring Boundary L-NE-01]

[Model Evidence Level: M1]

[Site Evidence Level: E0]

[Handling Method: Long-distance re-measurement, approach not permitted, sampling not permitted.]

This was a glance earned through fifteen years of accumulation.

What others saw were ruins; what he saw was a projection of a torn-apart motherboard.

Beneath the piles of rubble should be a complete vascular system that once operated, and by now, he could roughly determine its trajectory.

At ten in the morning, the G-Explorer-C was released from the towing rack.

Jiang Lin had it probe along an arc, advancing slowly close to the surface like a cautious black arthropod.

The sacrificial layer at the foot tips recorded a contact matrix every ten meters, the low-frequency vibration pickup injected synchronously, and the thermal infrared captured frames every thirty seconds.

Over the first four hundred meters, several weak anomalies popped up successively: foot-tip pressure fluctuations, low-frequency echo attenuation, and brief magnetic field disturbances.

Single point, single channel, E0, of no operational significance.

Jiang Lin didn't even raise his eyelids, letting them pass directly.

In Northeast Seventy-Three, a single anomaly did not constitute evidence; this was an iron law carved into the machine's state machine, and an instinct carved into his spine.

The true test arrived at the six-hundred-and-seventy-meter mark.

In the drone's overhead view, that was merely a slightly lighter-colored area amid the grayish-white rubble slope, almost indistinguishable to the naked eye.

But at that moment, the foot-tip contact curve of the G-Explorer-C showed three offsets simultaneously.

The leading-edge pressure was normal, but the trailing-edge rebound was half a beat slow.

The low-frequency pickup captured an abnormal attenuation.

The thermal infrared showed that the cooling rate on the inner side of the arc band was a notch slower than that on the outer side.

Three types of weak anomalies interlocked in the same area for the first time.

Red characters suddenly popped up on the screen:

[Evidence Level: E2]

[Recommendation: Cease advance]

[Prohibition: Do not approach the center]

The machine stopped, withdrew three meters, and stabilized on the safe side.

Jiang Lin did not rush to approach.

He instructed the robot to deploy the E-01 disposable environmental recording box; short spikes hammered into the surface to fix it, and it immediately entered a silent recording state.

At the fortieth second, that slightly lighter-colored area behind him collapsed without warning.

A small patch of the rubble slope caved in entirely, revealing a bottomless black hole about half a meter in diameter. Dust surged, rolling in the early morning oblique light into a small grayish-white cloud.

Jiang Lin stared at the newly collapsed cavity, but in his heart, there was not a shred of wishful thinking.

This was the judgment he had written into the state machine, calculating this step for it forty seconds in advance.

For a machine, if every seemingly cowardly retreat of its was proven correct afterwards, then it was no longer conservative, but precise.

After the dust raised by the collapse dispersed, the edge of the newly appeared cavity revealed a small piece of something Jiang Lin had waited fifteen years for.

The drone's close-focus lens zoomed in, and within the frame, a grayish-black arc-shaped contour protruded from the gaps in the rubble.

It was too straight, and the edges were too regular; no natural rubble would grow into this shape.

Jiang Lin did not let the drone get any closer, as low-altitude rotors would disturb the overburden; instead, he had the G-Explorer-C detour along a safe arc, approaching step by step.

Advancing to a distance of three meters, the G-Explorer-C extended its front probe rod and gently brushed aside the loose rubble at the edge.

What was revealed underneath was not rock.

It was a section of dark grayish-black composite material surface, dense honeycomb-like cracks crawling all over the outer layer, with traces of post-ablation ceramification at the edges.

It was too familiar.

It belonged to the same engineering lineage as the shell of the PMCU-17, the lightweight composite armor section at a depth of nineteen meters, and the sheared tubular component section at twenty-seven meters.

Jiang Lin's hand dragging the image paused for a moment, then continued to magnify the fracture texture.

This was something built by the same dead civilization using the exact same set of logic.

The probe rod continued clearing, and three minutes later, an arc-shaped contour was fully exposed to the surface.

The estimated diameter was twenty-two to twenty-six centimeters, part of a tubular component, with a direction basically consistent with L-NE-01, and an angular difference of only six degrees—even closer than the PMCU-17 cooling interface orientation.

The MPS-Agent α printed a new tag on the screen:

[L-NE-01-A: Suspected Outer Ring Tubular Component Remnant]

[Evidence Level: E2]

[Recommendation: Find natural fracture ends, do not contact the main body]

Jiang Lin did not touch it.

It was still embedded in the collapse structure; any disturbance might alter the local stress, turning this small piece of evidence that had survived for decades into the inducement for a second collapse.

He had the machine continue searching along that direction, and at one-twenty in the afternoon, the second linear protrusion appeared.

This time, it was a fracture in the true sense.

The fracture was 1.2 meters long, half exposed, and the borescope probe slowly approached.

Within the image, a circle of layered structure emerged from the dust.

The outermost layer was the ablation-ceramified protective layer.

Further inward was the pressure-bearing shell with honeycomb cracks.

Sandwiched in the middle was a layer of light-colored thermal insulation material.

And the innermost side was not a single channel, but at least three parallel arc-shaped micro-channels, resembling blood vessels surviving after being jointly destroyed by high temperature, high pressure, and long-term corrosion, with a thin and uneven layer of white-gray crystals covering the dark inner walls.

This was a fluid channel system designed with complex flow-splitting.

That thin layer of crystals on the inner wall of the fracture showed uneven deposition along the flow direction of the channel.

This meant something had once flowed through these three parallel blood vessels.

It could be a cooling medium, phase change cycle residue, or some kind of high-stability engineering fluid he could not yet name at this moment.

Jiang Lin had the machine record three hundred photos of the fracture from different focal lengths and different light source angles.

White light, near-infrared, oblique light, and thermal infrared were all archived.

Only then did he execute the sampling.

Without touching the main body, he used a miniature clamp to gently take a small piece of crystalline attachment from a piece of debris on the outer side of the fracture that had naturally fallen off and completely detached from the pressure-bearing path.

Sample number automatically generated — [N73-LNE01-CoolantResidue-01]

Sealed, archived, coordinates written, and photo comparisons before and after sampling completed.

Until this moment did Jiang Lin write down the first truly meaningful judgment of the day in his paper notebook.

[Probability that L-NE-01 is a remnant of an artificial tubular component has increased significantly.]

[Suspected TM-7 outer ring thermal management network remnant.]

Suspected.

Not confirmed.

But this was already the first time since this round of expedition that he allowed himself to write the two words "TM-7 outer ring" into the field conclusions.

At two in the afternoon, the MPS-Agent α re-fitted the outer ring boundary direction based on the positions of L-NE-01-A and this new fracture.

Between the new direction line and the old PMCU-17 excavation point, an intersection area was fitted out.

It was not the core collapse zone, but beneath a shallow rubble slope slightly outside the northeastern side of the old fissure mouth.

Back when he excavated the PMCU-17, he didn't even give that place a second glance.

Because at that time his goal was only to drag out that black monolith, not to search for the entire set of original network behind it.

Looking back now, the answer was already very clear.

The PMCU-17 was never squeezed out by the strata in isolation; it was sheared off from some outer ring service utility corridor or thermal management branch line, and then pushed by tectonic movement near the old fissure mouth.

And L-NE-01 was a part of that residual branch line.

This meant that scattered underground in Northeast Seventy-Three was not just this single severed nerve of the PMCU-17.

It also had blood vessels, branch lines, and an entire outer ring structural network torn apart and buried beneath the grayish-white surface.

Looking at the fitted map, Jiang Lin felt no excitement; instead, he felt even heavier.

Finding the pipelines was not taking a step closer to the answer.

Rather, it proved that this collapse zone was far more complex than he had previously thought.

The PMCU-17 was only an exposed nerve ending; the true outer ring might be like a giant net buried beneath this dead silence Wasteland.

And deeper within the net lay the sealed boundary of the inner ring.

The heart of that silent, regional-level underground computing array that might still retain a trace of residual warmth.

In the evening, he terminated the on-site advancement for the day.

The reason was simple: suspected outer ring tubular component remnants had been found, and the first naturally exfoliated crystal sample had been collected.

This was already enough to change the mission structure of the entire secondary expedition.

Continuing to push forward was not bravery; it was greed.

When night fell, the G-Explorer-C crouched beside the towing rack, the scratches on its foot-tip sacrificial layer shimmering with a fine white light under the low-power lamp.

It hadn't traveled very far today, yet for the first time, it brought back something genuine.

Even though it was just a small tube of crystal residue, a fracture image, and a set of thermal lag curves so weak they could hardly be called anomalies.

But from this moment on, the PMCU-17 was no longer isolated evidence.

The outer ring of Northeast Seventy-Three had revealed its second fracture.