Siheyuan: I, Shazhu, started out as an army and became a general.

Bohai Bay, a top-secret naval base.

The biting sea wind whipped up white foam, relentlessly crashing against the breakwater with a dull thud. But inside the enclosed dry dock deep within the base, the atmosphere was even more somber than the dead of winter outside.

In the center of the dock, a huge, streamlined black behemoth lay quietly.

This is the Republic's first-generation nuclear submarine, the backbone of the nation, and a thorn in the side of all the technical personnel present.

"Mr. He, please put on your headphones and listen."

Huang, the chief designer of the nuclear submarine, pointed to the microphone on the test bench. His hand trembled slightly, and his voice sounded rough, as if it had been sanded.

He Yuzhu didn't waste any words, grabbed the earphones and put them on his head.

The next second, his face twitched violently, and he ripped the headphones off.

"Clang! Clang! Clang!"

The noise was audible even through the headphone wires. It didn't sound like some high-tech national equipment; it sounded more like that old, leaky Liberation truck at the entrance of the alley, panting and dancing in the mud.

"The data is in." Old Huang handed over a crumpled report, his eyes bloodshot. "160 decibels. Forget sonar, any American who isn't deaf could probably hear it from halfway across the Pacific."

"160 decibels?"

He Yuzhu slammed the report on the table, took out a box of Daqianmen cigarettes from his pocket, and the guard Zhang Xiaowu, who was standing next to him, quickly came over and lit it.

"call--"

He Yuzhu exhaled a smoke ring, a cold, hard smile curving his lips: "Old Huang, this isn't a submarine, it's clearly an underwater hearse prepared for our soldiers."

"If we take this thing out, we don't even need anyone to drop depth charges. We're like a mobile radio station, shouting all over the world, 'I'm here, come and shoot me!'"

The words were harsh, like knives.

But no one present refuted it.

A gray-haired technical team leader wiped his face, his voice trembling with tears: "General Manager He, we really did our best... The Soviet experts burned all the blueprints when they left, we had no resources!"

"We lack high-precision reduction gears, silent pumps, and we can't even figure out the cavitation effect of propellers. This is the current limit of our industry."

"limit?"

He Yuzhu pointed at the enormous vessel with a cigarette between his fingers.

In previous records, this generation of submarines was jokingly referred to by the West as "underwater tractors." To guard the country's borders, young soldiers drove these "iron coffins," which could be exposed at any moment, to fight to the death against heavily armed enemies.

That wasn't a tactic; that was risking one's life.

But now that he's standing here, this blood debt is no longer owed.

[Ding! Host detected as being located at a national level-two classified research node: a nuclear submarine base.]

[Check-in successful!]

[Reward: Formula for materials used in third-generation nuclear power plant sound-absorbing tiles and active noise-absorbing tiles!]

[Host has been detected to possess "pump-jet propulsion technology". Retrieve immediately?]

"extract."

He Yuzhu's eyes hardened, and he strode to the huge design board.

He casually picked up a red and blue pencil and drew a big "X" on the propeller design drawing that had kept countless experts up all night.

The pen tip tore through the drawing paper, making a piercing "sizzle" sound.

"We don't need this propeller."

He Yuzhu's voice wasn't loud, but it was like a thunderclap, silencing the entire control room.

"No...no propeller?" Old Huang nearly dropped his glasses in shock. "Mr. He, without a propeller, are the sailors supposed to paddle with their hands? This is no joke!"

"Who's joking with you?"

He Yuzhu turned around, and the oppressive aura of a superior instantly spread out.

"The cavitation generated by the rotating propeller is the biggest source of noise in our 'tractor.' As long as this thing is still turning, even if you wrap it in a blanket, it will still be a tractor."

"So you mean...?"

"Modify pump spraying."

With a flourish of his pen, He Yuzhu sketched out a complex structure with a flow guide ring in the blank space of the drawing.

"The exposed propeller has been replaced with an internal pump-jet propulsion system. Simply put, it's replacing the 'fan-driven' system with a 'jet-driven' system, utilizing a high-speed jet stream for propulsion."

He pressed the tip of his pen heavily on the drawing:

"And with the new sound-absorbing tiles I've added to the drive shaft, Lao Huang, I'm telling you this—once this system is installed, the noise level of this submarine will drop below 100 decibels!"

Below 100 decibels?!

The control room became so quiet you could hear a pin drop.

In this day and age, what does a submarine with a noise level below 100 decibels mean?

This means that in the depths of the ocean, it's just a murmur blending into the background noise. That's the real "oceanic black hole," a silent invitation from the King of Hell!

"These blueprints... these geometric surfaces..." Old Huang leaned closer to the blueprints, his pupils contracting sharply, his fingers trembling. "President He, this is theoretically feasible, but practically impossible! It requires a seven-axis or even higher-level CNC machine tool, and our country hasn't even mastered five-axis CNC yet..."

"Machine tools?"

He Yuzhu grinned, revealing a set of white teeth; his smile was wildly arrogant.

"Does something that machines can't make mean that humans can't make it?"

He stubbed out his cigarette, cracked his knuckles as he moved them.

"Old Huang, prepare a cleanroom for me, completely sealed off. I'm not coming out, and nobody's coming in. Machine tools won't do; I'll be the machine tool!"

"You're doing it yourself? But... you're a general!"

"What happened to the general?"

He Yuzhu took off his military overcoat and casually tossed it to Zhang Xiaowu, then walked towards the workshop wearing only a thin shirt. His back was ramrod straight, like an unshakeable mountain.

"Once underwater, the enemy's torpedoes won't recognize any admiral."

He didn't turn his head; his voice echoed in the empty dock:

"So that our soldiers don't have to drive 'tractors' to their deaths, so that our borders aren't treated as our backyard, I'd rather be dismantled and used as fuel than have to hand-make parts!"

"Let's get started! I'm going to prepare a big gift for these foreign devils!"