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

The drizzle has been falling since noon, and a shallow layer of water has accumulated on the bluestone slabs at the entrance of the alley. The iron pot lid of the soy milk stall makes a muffled sound as the raindrops tap on it.

The crew-cut clerk squatted behind the stall, his old cotton-padded jacket collar turned up to cover half his face, holding an enamel mug in his hand, the soy milk inside long since gone cold.

His gaze pierced through the gaps between the row of low gray brick houses across the alley, fixing fixedly on the back door of the pawn shop twenty meters away.

The shop had a faded wooden plaque hanging on it, and a half-broken cloth curtain was propped up by bamboo poles at the entrance. The curtain was blown by the wind, revealing a dark passageway inside.

He's been squatting since 9 a.m., seven hours now. The crew-cut officer has changed his squatting position three times, and his left leg is so numb that he can't feel it anymore.

"Still not moving?" A low, husky voice came from behind him. It was Old Zhou, who was squatting to his right with the fake bicycle being repaired.

"no."

"Director Wang was referring to around 4 PM, which is about 10 minutes away."

The flat-headed clerk didn't reply. He placed the enamel mug at his feet, reached his right hand into the inside pocket of his cotton-padded jacket, touched the cold ID holder, and then withdrew it.

The soy milk stall owner added a ladle of water to the pot, and the steam carrying the smell of soybeans wafted over. The crew-cut clerk turned his head to avoid it, but his gaze never moved an inch.

At 4:08, the back door of the consignment shop was disturbed.

The door was pushed open a crack, and a hand reached out to look to the left and right before the entire door was pulled open.

The old shopkeeper's short, stocky figure emerged from behind the door, carrying a wooden crate in his arms. The crate was bound twice with hemp rope in a crisscross pattern and wrapped in oiled paper. Judging by its size, it looked like it contained a thermos.

The shopkeeper didn't carry an umbrella; he walked quickly toward the east entrance of the alley, heading toward the post office on the front street.

The crew-cut clerk stood up, a sharp numbness in his left leg almost tripping him. He steadied himself by grabbing the edge of the stall table, then made a gesture behind him: three fingers, first spread apart and then clenched together.

Three plainclothes officers got up from different positions. One followed from the entrance of the grocery store, one walked slowly towards them from the other end of the alley, and the third went around to the side door of the post office on the front street to wait.

The shopkeeper walked at a brisk pace, his shoulders hunched as he walked, the box pressed against his chest without being switched hands, clearly indicating that the contents were heavy.

Raindrops pattered on his gray cotton-padded jacket, soaking his back.

The post office was just around the corner of the street. Above the green-painted wooden door hung a white sign with black lettering that read "Xuanwumen Post Office." The dark green tin mailbox at the entrance gleamed dimly in the rain.

The shopkeeper pushed open the door, went straight to the counter, placed the wooden box on the counter, and took out a folded piece of paper from his pocket to start filling out the mailing form.

The crew-cut clerk paused outside the door for three seconds, waiting for the people behind him to arrive, before stepping into the post office.

He didn't call out or show any identification; he simply walked quickly to the counter and grabbed the shopkeeper's hand as he was writing.

The shopkeeper looked up, and it took him less than a second for his expression to change from bewilderment to terror.

"Don't move."

At the same time, the side door of the post office was pushed open, and Director Wang walked in.

He was wearing an old dark gray trench coat, the collar buttoned up tightly, and he was not carrying anything in his hands, but two people were following behind him, one carrying a toolbox and the other carrying a seal and a notebook.

"Open the box." Director Wang walked to the counter, his tone as flat as if he were saying it had rained that day.

The shopkeeper's lips trembled slightly, and his eyes darted around the doorway. Finding that all the exits were blocked, he felt as if his bones had been removed, his shoulders slumped, and his hands hung limply at his sides, no longer struggling.

The man carrying the toolbox stepped forward, cut the hemp rope with pliers, lifted the oil paper, and pried open the wooden box lid.

Inside the box was a thick layer of old cotton wadding, with a cylindrical object wrapped in yellow wax paper embedded in the middle. It was about the length of an adult's forearm and its ends were sealed tightly with tape.

The flat-topped clerk put on gloves and carefully peeled off the yellow wax paper.

Inside is a high-voltage pulse rectifier tube, with the serial number and production batch printed on its surface. The anode structure inside the glass shell is clearly visible under the light.

Director Wang stared at the rectifier tube for a few seconds without saying a word, then pointed his finger to the bottom of the box.

The flat-topped clerk continued flipping through the pages, and at the very bottom of the cotton wadding was a light blue notepad folded into a narrow strip.

When unfolded, the mailing address and recipient's name are written on it.

Li Wende, transit station of Aksai Mining Bureau, Gansu.

Director Wang took the note in his hand, looked at it over and over in front of the light bulb above the post office counter, then folded it and stuffed it into the inside pocket of his trench coat.

"Take them all away, people and their suitcases."

As the shopkeeper was being dragged out by two plainclothes officers, he suddenly spoke, his voice shrill and broken: "I don't know anything. Someone paid me to send something. I don't know any Li Wende..."

Nobody paid him any attention.

Back in the basement of the security office, a body search lasted forty minutes.

The shopkeeper's outer garment had been opened, revealing a flat envelope sewn inside, with an oval purple stamp on the lower right corner.

The flat-headed clerk held the envelope up to the light to read the words on the seal, his voice trembling as he read them aloud.

"Zhang Shouzheng, Inspection Department, Third Electronics Factory."

This name has been in the factory's archives for three years. Zhang Shouzheng passed away in 1952 due to illness. He was a senior engineer in the laboratory department.

Director Wang stood across the interrogation table. When he heard the name, he didn't react immediately, but instead slowly tapped the table three times with his fingers.

The envelope contained a thin sheet of wax paper with a picture drawn in tiny characters. Several frequency numbers were marked in the upper left corner of the picture, and a series of azimuth markings were on the right.

Director Wang recognized it in less than five seconds: it was a sketch of the frequency band deployment for the Northwest military receiving chain. Although incomplete, it covered the core frequency band allocation for the No. 3 direction finding station and the No. 4 relay station.

"Zhang Shouzheng is Lao Lei's fellow disciple." Director Wang's voice was very soft, as if he were talking to himself.

The flat-headed clerk was registering the list of physical evidence when his pen paused briefly on the paper.

"From 1949 to 1952, Zhang Shouzhen and Lao Lei were in the same experimental group, responsible for frequency calibration and deployment records in electromagnetic experiments." Director Wang put the wax paper back into the envelope, sealed it with wax, and signed his name and date on the seal.

"This stamp is an internal seal used only by the laboratory engineer. It should have been destroyed and archived after Zhang Shouzhen's death."

"How did it end up in a pawn shop manager's compartment?" the flat-haired clerk asked.

"Someone kept it and used it for three years." Director Wang sealed the letter and put it into the metal cabinet. He turned around and said, "The Grey Pigeon line didn't just start last year, nor could it be built by Meng Dechang alone. Its roots are in the older generation of core technical personnel in the factory."

He was silent for a few seconds, his gaze falling on the mailing address in the physical evidence register.

Li Wende, transit station of Aksai Mining Bureau, Gansu.

Previously, Li Huaiyuan stated that the destination was the Hongliugou Material Transfer Station in Gansu, and the receiving unit was listed as the local construction bureau. Now, another Aksai Mining Bureau has appeared.

Two transit stations in Gansu, two different recipients and company names, do the routes intersect or diverge?

Director Wang switched to a flat-top job.

"Investigate the relationship between Li Wende and the head of the supplies department." He looked up at the high window in the basement that let in the light of the water, his voice low. "We're close to catching Grey Pigeon."

The basement was cold and quiet, with only the autumn rain continuing to fall outside the window.