Chapter 163: Offline and Reconnected

2:40 a.m. The dormitory’s fluorescent tube had gone completely dark, leaving only the laptop screen to cast a cold white glow. Lin Chen leaned back in his chair as a dull pain pulsed through his left ankle, like fine needles slowly grinding in the seam of the bone. He did not move. He only drew his foot inward against the chair leg to keep pressure off it. On the screen was the packet-capture interface, and in Wireshark’s filter bar a dense stream of red TCP Retransmission warnings kept flashing.

The factory firewall had isolated traffic through a whitelist. The heartbeat packets sent by his script had been intercepted as anomalous traffic. The ConnectionRefused error did not mean the physical link was down; it meant the security policy was rejecting the request. He could not change the factory’s rules, and Old Zhao was not going to reconfigure a security group for one student’s script. The only option was to make the script “disguise” itself as normal business traffic. He opened a new Python file and rewrote the heartbeat module. The fixed five-second interval became randomized jitter. The plain-text PING was wrapped inside an HTTP OPTIONS header to imitate a browser preflight request. The code was not long, but the timeout thresholds and retry backoff algorithm needed repeated tuning. He typed the final line—time.sleep(random.uniform(3.8, 5.2))—saved, and ran it. A green 200 OK popped up in the terminal. The disconnect rate dropped from twelve percent to three per thousand.

He rubbed the space between his brows. His stomach cramped with a hollow spasm. The cup of instant noodles on the desk had long since gone soggy, a white slick of oil floating on the broth. He lifted it and took a sip. It was bitter with salt. His phone screen was still lit; the banking app showed a balance of 35.3. One box of imported sodium valproate cost forty-eight. The domestic version could not control it. His mother had said Xiaoman bit through his lip during a seizure the night before, and the clinic doctor had advised changing medication, but the imported drug was not covered by the rural insurance plan. He opened the calculator and pressed a few keys. If the project subsidy was paid by hours worked, he could get two hundred a week. Three weeks—just enough for a month’s medicine. But only if Friday’s defense passed, and only if Old Zhao’s thirty thousand records were settled on time. The numbers lined up in his head like a queue, stripped of emotion, nothing but arithmetic.

He switched back to the PPT. Slide five: Why Us. He deleted what he had originally written—“comprehensive technical stack, strong learning ability.” The cursor blinked there for several seconds. He thought of the old industrial control machines in Workshop No. 3, their casings dark with grease; thought of Old Zhao’s furrowed brow as he crushed out a cigarette; thought of those afternoons when, to save eight hundred yuan in hardware costs, he scavenged dismantled parts in the secondhand market and soldered wiring, flashed firmware, and assembled things himself. Then he typed again:

“We understand the real constraints of the production line. We do not rely on expensive new equipment; we use software redundancy to compensate for aging hardware. We do not pursue theoretical optimality; we guarantee uninterrupted data flow under power loss, network outages, and heavy interference. Low cost, high fault tolerance, replicable.”

When he finished, he read it once through. There was no sentiment in it, only fact. He changed the slide background to dark gray and bolded the text. The language of technology had been stripped of its rough, makeshift edges and fitted into the frame of a policy document. It was not packaging. It was a translation necessary for survival. He poured hot water into another bowl of noodles and watched the steam rise. He did not eat. He only watched it disperse into the cold air. The glow of the screen lay cold and pale across his face. He typed slowly, while beneath the desk his left foot tapped lightly against the floor, the pain already numbed into a kind of background noise.

At seven in the morning, when the sky was only just beginning to pale, Lin Chen stuffed the computer into his backpack, locked the door, and headed downstairs. The moment his left foot touched the ground, pain climbed up his calf. He shifted his weight to the right, his gait slightly uneven but steady in rhythm. On the bus to the factory district there were only a handful of early-rising laborers. The carriage smelled of soy milk and machine oil. Leaning against the window, he closed his eyes and ran through the defense in his head. Five minutes. Only three things: the pain point, the solution, the validation. No showing off. No empty promises.

At exactly nine, he arrived at Workshop No. 3. The smell of oil mixed with the scorched tang of metal cutting rushed at him. Old Zhao was already standing by the control console, a thermos cup in hand. Lin Chen connected his laptop to the internal network and ran the new script. Data streamed smoothly across the screen. In the log window, heartbeat packets went out at irregular intervals, each one returning 200.

“It’s through.” Old Zhao leaned closer to look. “Without changing the policy?”

“No changes,” Lin Chen said evenly. “It goes through the business channel and doesn’t touch the security rules. If the factory upgrades the firewall later, the script will automatically downgrade to low-frequency polling to keep the basic data flowing.”

Old Zhao unscrewed his thermos, took a drink, and nodded. “Good. I’ll send you the inventory list this afternoon. Paid per item—eight mao each. Settled at month’s end. Kid, your head turns faster than the machines.”

Lin Chen said nothing. He only copied the verification report from his USB drive onto Old Zhao’s computer. When he turned to leave, a sharp stab flared through his left foot again. He did not break stride, only shifted his balance more firmly. Eight mao a line—thirty thousand lines made twenty-four thousand yuan. That money would fill the hardware gap in the application proposal, and it would keep Xiaoman’s medication from running out. Only when the accounts balanced could the road continue forward.

At two in the afternoon, he returned to the dormitory. His roommate was still asleep. He opened the computer and finished the final proofread of the PPT. Font, alignment, animation timing—everything adjusted to the bare minimum. He exported a PDF and backed it up to both a USB drive and the cloud. Then his phone vibrated. Professor Zhou had sent a WeChat message:

The Friday defense has been moved up to 9 a.m. Two enterprise reviewers from the Science and Technology Department are coming. They care about implementation cost and maintenance difficulty. Be ready to get pressed hard on the hardware replacement plan in your PPT.

Lin Chen stared at the screen. Moved up. Enterprise reviewers. He opened the appendix slides. Inside were a cooling retrofit diagram for the Raspberry Pi 4B and the waterproof sealing steps for secondhand sensors. He knew these “makeshift fixes” looked crude to academics, but in a factory they could be lifesaving. What he needed to do was translate “crude” into “engineering adaptation.”

He opened a new document and began listing questions he might be asked.

1. How is industrial-grade stability ensured for the Raspberry Pi? 2. What are the service life and calibration cycle of the secondhand sensors? 3. What are the maintenance costs and personnel dependency of the script?

He wrote out the answers one by one, relying not on theory but on measured data. Seventy-two hours of continuous operation at a workshop temperature of forty-two degrees Celsius with no crashes. After encapsulation, the sensors reached IP65 moisture protection. Once deployed, the script required Old Zhao’s network administrator to do no more than reboot the router once a week. He did not type quickly, but every word landed somewhere solid. Outside the window came the cries of a scrap collector, and the intermittent rattle of a tricycle chain. Lin Chen paused, rubbing his stiff neck. His left foot had gone completely numb, like a block of wood no longer belonging to his body. He stood up and walked slowly to the window. The leaves on the plane trees downstairs had yellowed by half. When the wind rose, they spun as they fell.

His phone vibrated again. This time it was a voice message from his mother. Behind her voice was the ticking sound of the clinic. “We bought the medicine. The doctor said let him take half a box first and see. Are you coming back Friday? Xiaoman keeps asking when his big brother will take him to see the trains.”

Lin Chen held down the voice key and was silent for two seconds. “Defense Friday morning. I’ll come back in the afternoon. I’ll take him.”

He lifted his finger, and the message sent successfully. Returning to the desk, he ironed the shirt he planned to wear for the defense. The fabric was old, the collar edges already frayed, but it was clean. He buttoned the top button and smoothed his hair in front of the mirror. The person reflected there had hollowed eye sockets and stubble left unshaven along the jaw, but the gaze was calm.

He knew that in Friday’s conference room there would be no code, only people. And what people cared about was not how advanced the technology was, but whether it could stand firm in the mud, whether the numbers made sense, whether it could ensure that a child convulsing in a clinic got his medicine on time, that the son of an old farmer did not have to keep grinding away in a workshop until dawn.

He switched off the desk lamp and lay down. His left foot rested over the edge of the bed, the pain slowly ebbing back in the dark. Tomorrow he still had to make a trip to the electronics market to buy some shielded cable and heat-shrink tubing. And he needed one more backup USB drive for the defense. Night wind slipped through the window crack and stirred the cover page of the application packet at the corner of the desk. Paper brushed against paper with a faint rustling sound. The road ahead was still long, but every step had to land solidly.