I started with a ship full of max-level veterans, and I'm just a complete noob.

After the dedicated line receipt was sealed, Jiang Ming stayed in room 502 for the night shift.

The raindrops gradually increased in intensity, continuously tapping against the windowpane of the research lab. He first put the Aksai photographic paper and receiver drawings into the safe, and then put the high-frequency silicon tube finalization report, which was to be sent to the Fifth Academy the next morning, into a separate red-edged envelope.

On the other side of the workbench, Lei Zhenbang's manuscripts are still laid out chronologically.

During a break in the communications room when they were reviewing the time stamps for multiple stations, Jiang Ming checked the numbers page by page and re-filed the batch of old papers.

The materials on the table belong to two separate lines of secrecy: one points to the Northwest airspace and the overall demonstration of the Five Academies, and the other leads to clues about Lei Zhenbang's old case and his background.

Two lines, separated by half a tabletop, both pressed down on Jiang Ming's hand on this rainy night.

He put the pen back in the pen holder and his gaze fell on the half sheet of electromagnetic field calculation paper left by Lei Zhenbang.

The signature in the lower right corner of the page was soaked in water and only the two characters "Zhenbang" could be made out. The ink residue in front of the signature could not be restored.

Jiang Ming put the transparent cover back on and was about to lock the drawer when he heard two light knocks from outside the corridor.

Comrade Song pushed open the door and came in. Rainwater dripped from the brim of his hat onto his shoulders. He didn't cross the security line, but just stood by the door and said, "There's an extra bicycle in the yard, and it's in the wrong place."

Jiang Ming pushed the drawer halfway back, looked up and asked, "When did you find it?"

"There was no vehicle in the yard before the shift change. I just patrolled to the wall of the boiler room and the vehicle was already parked there, with the front wheels facing the side door. It wasn't locked and there was no record of it."

Vehicles inside the 502 compound have designated parking areas. Even if delivery personnel only stop for a few minutes at night, they must register their name, company, and entry/exit time with the gatekeeper.

Parking a car is best done near the boiler room wall, away from the main building windows and close to the side door, as it's a popular spot for people familiar with the security routes within the compound.

Jiang Ming got up and grabbed his work jacket, but Comrade Song raised his hand to stop him.

"You stay inside, I'll handle this first. The security team has already sealed off both doors."

Comrade Song turned and went downstairs, took out canvas gloves and a flashlight from the duty cabinet, and led two guards along the wall toward the boiler room.

The old bicycle leaned against the drainpipe, its rear fender covered in fresh mud, but the chain and pedals were spotless, and the production label on the frame had been filed off.

The guard first checked the basket, seat, and tool bag, but found no wires, medicines, or numbered items. However, there was an iron clamp stuck on the right side of the handlebars.

Folded white paper was pressed under the metal clip, with the corners facing the main building, so anyone who approached the handlebars could see it.

Comrade Song asked the guards to step back, put on gloves, removed the iron clamp, put the white paper into the temporary evidence tray, and then checked the surrounding footprints and the top of the wall.

The rainwater washed away the marks on the ground, but half a rubber-soled shoe print remained in the drain near the side door, though its direction was impossible to determine.

The boiler room staff only heard the sound of rain and the rustling of the metal sheet in the wind; no one saw the person pushing the cart enter the yard.

Comrade Song left the bicycle where it was, arranged for guards to stay at the scene, and carried the evidence tray back to the second floor.

Jiang Ming had cleared the table, leaving only a clean glass plate under the lamp.

When the white paper is unfolded, a line of blue-black pen writing is visible in the center.

Yuan Lei's son?

Jiang Ming read it twice, his finger hovering over the glass plate without touching the paper.

The name Yuan Lei has never appeared in public materials. No one has ever used these two characters to refer to Lei Zhenbang in Lei Zhenbang's case files, confidential system confessions, or old archives of the Third Electronics Factory.

The letter writer knew about the old case and deliberately placed the word "Lei" at the end, as if using a term that belonged only to the old network of relationships.

Jiang Ming couldn't be sure whether the line of text was a test of identity or a reminder of a relationship that had been deliberately severed.

He picked up the internal phone and connected to the duty desk of the ministry's security department.

"This is Jiang Ming. There have been unregistered items delivered to Courtyard 502. The contents involve the old case of Lei Zhenbang. Please have Director Wang come over immediately."

The duty officer repeated the address and security level, and then switched to a dedicated line.

When Director Wang arrived, the rain had subsided, but his shoes were still wet from the water outside the yard. He first checked the on-site records upon entering, and then had the technician check the white paper fibers and the state of the ink.

The letter paper was made from ordinary office paper, and the edges were cut with an old-fashioned manual paper cutter. There was no watermark from the organization on the paper, and the folds avoided the writing.

The fountain pen ink is bluish-black, penetrates the paper quite deeply, and the strokes show scratch marks left by the hard-nib fountain pen.

Director Wang compared the handwriting with the existing samples of the suspects one by one. After reviewing several sets of radicals and penmanship habits, the technician shook his head.

"The same writing style cannot be found in the existing samples, and the paper and ink have not been put into the evidence database."

Director Wang took the magnifying glass and stared at the last stroke of the character "源" for a long time.

"The source is new, and it is currently impossible to determine whether it is good or evil, nor is it possible to determine whether the sender and the writer are the same person."

He instructed the technician to put the note into an evidence bag and then sign the time, place, and the name of the person in charge at the seal.

The old bicycles in the yard were also moved as a whole, and samples of mud from the tires, oil stains from the chains, and fibers from the handlebar grips were taken separately and will no longer be left for anyone to come into contact with.

Director Wang immediately adjusted the nighttime security measures for Unit 502, keeping the gatekeepers in their original positions and setting up three levels of observation points on the boiler room roof, at the alleyway outside the side gate, and in the dark corner of the main building staircase.

These locations are not directly connected to each other. Each group only knows its own monitoring range, and the situation is summarized and sent to the duty room.

After the deployment was completed, Director Wang returned to the confidential cubicle and laid out the floor plan of the compound in front of Jiang Ming.

"The outer patrol passes by the side gate every twelve minutes, and the boiler room staff goes out every half hour to check the water pressure. The person who delivered the note took advantage of two gaps and avoided the main gate lights."

Jiang Ming measured the distance from the side door to the boiler room and then checked the duty roster for tonight.

"There were no signs of forced entry on the door lock or the courtyard wall, so the other party may have known the old layout of this place, or they may have observed it for a few days in advance."

"Professional skills, clear objectives, and no lingering after delivery."

Director Wang put away the floor plan and turned his gaze to the evidence bag containing the slips of paper.

"His willingness to leave his handwriting indicates that he wants us to continue the investigation, or perhaps he is waiting for us to react."

Jiang Ming locked Lei Zhenbang's posthumous manuscript, the silicon tube report, and the Fifth Academy's task book into three separate drawers, and put the keys into his personal key pouch.

"The covert operations will be taken over by the Security Department. I will go to the Fifth Hospital as usual tomorrow morning. No matter what, we cannot delay the current project."

After listening, Director Wang did not advise him to stop working, but only requested that the special car route be changed temporarily and that an additional lead car without passengers be added.

As dawn broke, Da Liu brought in soy milk, fried dough sticks, and pickled vegetables. Seeing the extra guards in the corridor, he slowed his pace.

Jiang Ming took the breakfast and ate while flipping through the second batch of component aging schedule.

"Fang Xudong is in charge of temperature cycling. The six samples are divided into two groups. The first group will start with low temperature, and the second group will retain the original packaging state. Don't compress the steady-state record in order to rush the schedule."

Da Liu wrote down the requirements on a piece of paper on the back of the lunchbox lid, and then asked, "The spare capacitors and resistors have arrived. Can they be delivered together today?"

"Incoming materials are screened first, with leakage current, temperature drift and mechanical impact tested separately. Only materials that pass the tests can enter the receiving stage."

Wu Hanzhang pushed open the door and slammed a stack of purchase vouchers stamped with the factory's special approval seal onto the table.

"Tungsten rhenium probes, mica capacitors, and high-frequency connectors have been put into storage. Quartz tubes will arrive this afternoon. The factory has opened a separate material requisition window for 502."

Jiang Ming flipped through the vouchers and saw that several materials that originally needed to be allocated were now listed in the priority sequence. He then rearranged the timeline between the initial implementation and the second round of diffusion.

"Half of the scarce parts will be sealed up first, and the remaining parts will be used according to the project. No one is allowed to take away the test surplus as ordinary spare parts."

Wu Hanzhang agreed, but when he turned around and saw Director Wang in the corridor, the joy on his face vanished.

"Did something happen last night?"

"Someone brought me a piece of paper; the security department is checking it."

Jiang Ming did not reveal the contents of the note, and Wu Hanzhang did not ask any further questions. He simply put the purchase voucher back into the folder and prepared to go to the warehouse to oversee the handover.

As the special vehicle drove out of the Third Electronics Factory, the wooden window of the street newsstand had just been opened, and the newspaper deliveryman was bundling the day's newspapers on the table. Passing workers rode their bicycles across the still damp road.

Jiang Ming scanned several intersections through the car window, but did not find the same face appearing repeatedly, nor did he see any vehicles in unusual positions.

He knew that this observation could only rule out obvious tailing; if the deliveryman last night was truly professionally trained, he wouldn't easily show himself during the day.

After the special car entered the Fifth Academy, several structural and guidance engineers were already gathered outside the conference room.

A modified diagram of the missile body was spread out on a long table. The structural team insisted on increasing the rigidity of the gyroscope mounting bracket, but the guidance team refused to accept the resulting vibration transmission.

"The mounting bracket needs to be thickened, the quality center needs to be changed, and the cabling inside the cabin needs to be completely rearranged."

"If we maintain the current thickness and the resonance peak is positively pressurized in the working region, who will sign off on any problems that arise?"

Both sides have their calculations, and neither side is willing to concede on its own security boundaries.

Jiang Ming walked to the blueprints and had just made out the three frequency bands marked in red when the conference room door opened from the other side.

Qian Xuesen walked in, followed by a thin, middle-aged man wearing black-rimmed glasses. The man had a rolled-up diagram of the missile structure tucked under his arm. After entering, he first looked at the data in the hands of the two sides in the debate.

Qian Xuesen and the others quieted down and raised his hand to introduce, "This is Comrade Tu Shou'e, who is in charge of the overall structure of the missile."

Tu Shou'e placed the scroll on the long table, removed the outer binding, and spread the pages out along the tabletop.

Qian Xuesen looked at Jiang Ming, then at the guidance group seat where Ren Xinmin was located.

"From today onwards, the structure, guidance, and electronics will enter into a joint engineering effort. Any changes to the boundaries of any component must be discussed on the same diagram."

Tu Shou'e took out red and blue pencils and marked three positions in succession on the middle of the bullet.

On the drawing, three resonance peaks are pressing against the gyroscope's operating frequency band.