15: Welcome aboard, Dr. Su

Three days later.

The black iron fortress was quietly moored in the shadow of an abandoned building that offered relative shelter from the wind.

Inside the cockpit, Jiang Ran stood before a full-length mirror, testing the movement of his left arm.

Though there was still a slight pulling sensation, the piercing pain had vanished, and a thick scab had formed over the wound.

"Your recovery speed is incredible; your constitution is much stronger than an ordinary person's."

Su Qingyu's voice came from behind him.

She held a cup of coffee in her hand, but her gaze wasn't on Jiang Ran; instead, she was staring intently at a piece of equipment on the table in front of her.

It was a portable high-magnification electron microscope, the only possession she had brought from the yacht, the Seraphim.

"Since you're awake, come take a look at this."

Su Qingyu beckoned him over, her tone carrying a rare sense of gravity and unease.

Jiang Ran pulled on a tactical vest and walked over to the workbench.

On the microscope screen was a writhing mass of dark red liquid.

"What is this?"

"Remember those pirates who besieged the yacht that day? A few fell into the water and were shredded by the propellers."

Su Qingyu pointed at the screen. "This is a water sample I collected then; it's a mixture of their blood and the surrounding river water."

Jiang Ran narrowed his eyes, looking at the magnified image on the screen.

The scene was extremely horrifying.

Those red blood cells, which should have been long dead...

...were now like sentient beasts, frantically attacking and devouring other nearby microorganisms.

They were no longer fragile cells, but individual microscopic predators.

With every meal, their size swelled slightly, and black spines even began to grow from their edges.

"Do you see?"

Su Qingyu took a deep breath, her voice trembling slightly. "This isn't a virus, nor is it bacteria.

This is a highly active evolutionary medium."

"While you were unconscious these past three days, I've been observing this water sample.

The metabolic rate of these cells is thousands of times faster than that of normal organisms.

They are forcibly restructuring their genes, acquiring stronger survival forms through consumption."

She looked up, her cold eyes filled with fear of the unknown. "Jiang Ran, this heavy rain brought more than just water.

The entire underwater food chain is undergoing a terrifying reorganization.

Those dead 'Water Ghosts' were just failures because human genes are too fragile to withstand this evolution."

"But... what about the things that already lived in the water?"

Su Qingyu pulled up another comparison chart—a sample from an ordinary carp she had dissected earlier on the yacht.

The fish's bone density had tripled, its teeth had become serrated, and its fins had even begun evolving into 'claws'.

"Fish have simpler genetic structures and are more adaptable.

In this red-water world where big fish eat little fish, they are turning into true monsters.

And..."

She looked down at the sturdy deck beneath her feet. "Their evolutionary speed might be even faster than you think."

Jiang Ran fell silent.

He watched the microscopic cells slaughtering each other on the screen, and his sense of crisis surged.

If even microorganisms were fighting and evolving, then those already massive creatures in the deep waters... sharks? Whales?

Even just ordinary catfish—what would they grow into?

"No matter how thick the iron plating, it won't stop the tide of biological evolution."

Jiang Ran turned off the microscope screen, his gaze instantly becoming as sharp as a blade.

Su Qingyu's discovery had sounded an alarm for him.

He had thought reaching Lv2 would give him some peace for a while, but now it seemed he had to immediately start working toward Lv3.

"System, check Lv3 upgrade requirements," he thought to himself.

[Lv2 → Lv3 Upgrade Requirements:]

Hull structural steel: 100 tons (Currently met)

High-precision computing core: Requires a large amount of precious metals (Gold/Silver/Platinum) to reconstruct superconducting circuits to enhance fire control and radar computing power.

Biological/Special Materials: 0/1 (Requires hunting high-risk mutants to obtain biomass essence)

"Precious metals..."

Jiang Ran's gaze drifted through the porthole toward the city skyline, faintly visible through the torrential rain.

In this apocalypse, gold was no longer currency.

But it was the blood of industry and the soul of precision electronics.

To evolve the 'brain' of the black iron...

...and to possess a fire control system capable of locking onto and killing deep-sea behemoths, he needed a massive amount of gold to lay down a superconducting nerve network.

"Hold on tight, Dr. Su."

Jiang Ran turned and sat back in the pilot's seat, buckling his seatbelt, a predator's cold glint flashing in his eyes.

"Since the monsters underwater are evolving, we must keep up."

Su Qingyu gripped the handrail, puzzled. "Where are we going?"

Jiang Ran slammed down the throttle. The black iron fortress let out a low roar as it turned its bow, pointing straight toward the busiest part of the city center.

"To the city center, the Jiangcheng Financial Building."

"We're going to 'withdraw' some gold."

...The black iron fortress traversed the submerged urban canyons, the engine's roar echoing over the empty water.

This was once Jiangcheng's most prosperous CBD, the Central Business District.

Now, those skyscrapers that once pierced the clouds had become massive tombstones.

Only the glass curtain walls of the upper-middle floors remained above the water, reflecting the cold flash of lightning.

Torrential rain washed over these silent buildings.

Occasionally, shards of broken glass fell from dozens of stories high, hitting the water with a dull thud.

"We're here."

Jiang Ran watched the radar screen and slowly pulled back the throttle. The ship stopped beside the ruins of a uniquely shaped twin-tower complex.

This was the "Jiangcheng International Finance Center," once the economic heart of this city.

Su Qingyu leaned against the porthole, looking out at the bottomless black floodwaters, her face turning slightly pale.

"This is the location of the bank headquarters' underground vault... but the average water depth exceeds sixty meters.

Add to that the silt and building debris—without professional deep-diving equipment, going down there is suicide.

How do you plan to get it?"

"Who said I was sending a person down?"

Jiang Ran sat in the command chair, his fingers tapping rapidly on the console. "System, activate deep-layer metal detection."

"Filter out ordinary reinforced concrete; show only high-purity precious metal reactions."

[Scanning...]

The green light waves on the radar screen instantly turned a deep blue—a sonar beam with even greater penetration.

On the screen, countless cluttered lines were filtered out.

A few seconds later.

Deep within the building's foundation, a large, dazzling golden spot suddenly lit up.

Its brightness was so intense it even overshadowed all surrounding signals.

[High-purity gold element cluster detected.]

[Estimated reserves: 8 tons.]

[Depth: 55 meters underwater (Located in underground vault level B4).]

"Found it."

The corners of Jiang Ran's mouth curled up slightly.

Whether in times of prosperity or the apocalypse, bank vaults are always the most honest.

Eight tons of gold—this wasn't just wealth; it was the key raw material for evolving the black iron's brain.

"But it's so deep... and those are concrete explosion-proof walls."

Su Qingyu was still puzzled.

"Just watch."

Jiang Ran pressed the red capture button.

"Hum—" The hull vibrated slightly.

This time, the black iron fortress didn't just tentatively extend its tentacles; it operated at full power.

The hatches at the bottom of the ship swung wide open.

Four silver mechanical tentacles suddenly snapped together and intertwined.

Underwater, they didn't act separately.

Instead, they twisted tightly together like a braid, forming a "deep-sea heavy drilling arm" over half a meter in diameter.

The tips of the tentacles began to rotate at high speed, transforming into a sharp spiral drill bit.

It looked like a silver giant python, carrying the cold light of searchlights as it plunged vertically into the pitch-black water.

Aiming straight for the golden heart buried at the bottom of the abyss.