Chapter 50: Fatal Crash

No celebration party was held.

The champagne lay quietly in the storage room; the red banners were rolled up and shoved back into the cabinet. The joy of success, like a receding tide, vanished swiftly from the corridors of the office building, leaving behind nothing but a cold, damp beach soaked in reality.

Inside Du Yuze's office, the ashtray was full. Director Wang smoked cigarette after cigarette, no longer speaking of turbine-inlet temperatures or pressure ratios.

"Engineer Zhang... submitted a report," Director Wang stubbed his cigarette butt into the ash tray, "an early retirement application."

Du Yuze was in the midst of wiping a whiteboard, his movements pausing slightly at the words.

"He has worked his entire life here; his craftsmanship is unmatched by anyone in the entire factory," Director Wang's voice was somewhat raspy. "Now, a single machine, in just a few hours, has crushed a lifetime of pride. He simply cannot come to terms with it."

"Technological progress is always like this," Du Yuze's voice was calm. "The new will inevitably replace the old."

"That may be the logic of it, but human sentiment doesn't work that way," Director Wang sighed. "Xiao Du, you aren't wrong. But you must also understand that not everyone can accept being left behind by the times with the calm detachment that you do."

Du Yuze did not reply. He merely wiped the whiteboard a bit cleaner.

The office door was knocked upon—briefly, just twice.

A man dressed in a dark jacket walked in. He wore no uniform of any institution, yet carried an air utterly out of place in this R&D base. He glanced around the room, finally letting his gaze settle on Director Wang.

"Director Wang, I am Old K," the man introduced himself, his voice sounding like two stones grinding together. "From the Ministry's Security Bureau."

Director Wang stood up instantly, the exhaustion on his face replaced by a sudden vigilance. "What has happened?"

Old K did not answer, instead looking at Du Yuze. "And this is?"

"The Chief Designer of the project, Du Yuze."

Old K nodded, took a kraft paper envelope from his pocket, and placed it on the desk. "Operation 'VultureCatch' has made progress, but it's not good news."

Du Yuze lowered the whiteboard eraser.

"We located one of the 'Vulture's dead drops," Old K pulled out a chair and sat down with crisp, decisive movements. "The city library, a 1987 edition of *Heat Treatment Technology for Metallic Materials*, page 213."

Director Wang's breath hitched. "You took action?"

"An hour ago," Old K replied without any emotion. "We set up surveillance and prepared to close the net."

"Did you catch him?" Director Wang pressed.

"No," Old K's reply was like a basin of ice water. "He didn't show up."

Du Yuze spoke, his first words since entering the room. "How did he know?"

"He didn't know," Old K looked at Du Yuze. "But he was sufficiently cautious. He used a decoy—an entirely unrelated college student. Our operatives followed the student, and upon him, they found only the fake intelligence we had planted."

Director Wang's body swayed, and he slumped back into his chair. "The operation was compromised... we startled the snake in the grass."

"Yes," Old K admitted with complete candor. "We underestimated his cunning. With a single probe, he rendered over a month of our deployment worthless."

Dead silence fell over the office. The joy of success had been completely washed away, replaced by a piercing chill. The enemy was in the shadows; he had just seen through a meticulously prepared encirclement and emerged completely unscathed.

"There is worse," Old K pushed the kraft paper envelope to the center of the desk. "This is his 'reply'."

Du Yuze reached out and took the envelope, sliding out its contents. It was not a letter, but a small, encrypted slip of printed paper. There was only a single line on it.

【A magnificent roar. But the next note will be your requiem.】

Director Wang leaned over to take a look, his complexion turning instantly pale. "Roar... he knew about our test today! He knew it was a success!"

"Not only that," Old K's voice lowered further. "The word 'roar' is one that only engineers present at the scene would use to describe it. We checked; in the report you submitted to superiors, the technical terminology used was 'sonic boom'."

Du Yuze pinched the slip of paper between his fingers. The edges of the paper were somewhat rough, as if torn from an old-fashioned printer.

"You mean..." Director Wang's voice was trembling, "among us, there is one of his people?"

"That is the only explanation," Old K concluded. "The 'Vulture' is not only watching us from the outside; he has an eye growing inside our ranks."

This conclusion exploded in the small office like a bomb.

Director Wang stood up abruptly, pacing back and forth. "Impossible! Absolutely impossible! Every single person participating in this project has had their political background checked through three generations! How could there possibly be a problem?"

"Human hearts change, Director Wang," Old K's tone carried no emotion. "Money, status, or something else—there is always something that can cause a defense line to rot."

Du Yuze put the slip of paper back on the desk. "What does he want? Just a threat?"

"This isn't a threat, it's a declaration," Old K corrected. "He is declaring that our counter-measures have failed, and that he will resort to more drastic methods. Last time it was a blade; next time it might be the fuel pump, or the control system. As long as something goes wrong in a single place, the result will be the same."

"The aircraft crashes, lives are lost," Director Wang muttered.

"Therefore, starting now, the security level of the JY1 project is elevated to the maximum," Old K's tone became unquestionable. "All personnel will undergo re-investigation of their backgrounds. All external communications will be wiretapped. The laboratory will be under 24-hour dual surveillance; no one is permitted to approach core components alone."

Director Wang's lips moved as if to say something, but it ultimately dissolved into a heavy sigh. "This... this will severely slow down our R&D progress."

"A slow project is better than a non-existent project," Old K stood up. "Chief Designer Du, we need a list of all personnel who can access core data and components, as detailed as possible. Including their work habits, social relations, and even... financial status."

Du Yuze did not answer immediately. He looked at the slip of paper on the desk bearing the word "requiem," then raised his gaze to the structural diagram of the turbofan engine hanging on the wall. That machine, into which countless people had poured their blood and sweat, presented a sense of vulnerability in his eyes for the very first time. It was no longer a pure industrial miracle, but an undefended prey targeted by a venomous snake.

"I will compile the list," Du Yuze said. "However, Comrade Old K, this kind of passive defense will never find that 'Vulture'."

Old K paused in his steps and looked back at him. "Do you have any ideas?"

"The fact that he has eyes on the inside means he needs to receive intelligence," Du Yuze stood up, walked to the whiteboard, and picked up a marker. "Since he knew we used the word 'roar,' it shows the efficiency of intelligence transmission is very high, most likely completed right within the base."

"We are also investigating internal communication channels."

"No, do not only investigate electronic channels," Du Yuze drew a circle on the whiteboard representing the entire base. "The fact that he could use a book in the library as a dead drop shows he prefers physical methods. Such methods are harder to trace."

He paused, drawing many small dots inside the circle. "He needs a transmission node that everyone takes for granted, yet is sufficiently covert."

Both Director Wang and Old K stared at him.

"For instance..." Du Yuze's pen tip landed on one of the dots, "the cafeteria's tray return station. With thousands of trays circulating through here every day, who would notice a tiny slip of paper stuck to the bottom of a tray?"

Old K's pupils constricted slightly.

"Or perhaps, the ventilation duct opening in a public restroom. Or a bicycle parked in a specific parking space at a specific time," Du Yuze's voice grew faster, his train of thought like a rushing river. "Since he dared to leave that note, it is a form of showing off—an absolute self-confidence in his own abilities. He believes we would never think of these things."

Director Wang's mouth hung open, unable to utter a single word. He had never imagined that the place where he had worked his entire life concealed so many invisible corners.

Old K remained silent for a long time before speaking again: "Chief Designer Du, you seem... rather well-versed in these matters."

"I don't understand spies," Du Yuze put down the marker. "I only understand systems. Any system has its logic and vulnerabilities. Whether it's an engine, or a spy network."

Old K gave him a deep look, then nodded. "Your line of thinking, we will follow up on immediately. However, the security regulations must be enforced. Until the mole is caught, every single person in your project team is on the suspect list."

He paused and added, "Including you, Chief Designer Du."

With that, Old K turned and left the office, his footsteps vanishing down the far end of the corridor.

Director Wang slumped down despondently, leaving only himself and Du Yuze in the office.

Du Yuze walked back to his desk, turned off the computer screen displaying the perfect performance curves, and pulled up the personnel organizational chart of the entire project team.

Familiar names and photographs lined up one by one across the screen.

His gaze swept across each and every face.