Chapter 163: The Battle of the Invisible Ink Mark

Zhao Jianguo rode his bike, the tool box strapped to the rear seat, the rope tightening the metal edge into a slight deformation. The night wind pressed against his pant leg and slipped upward; the palm of his right hand was still faintly hot, as if he had just pulled it from a furnace.

Jia Dongxu followed behind, silent all the way, only glancing at the box now and then. When the two turned into a narrow alley of the family area, Zhao Jianguo suddenly stopped, lowered his head and stared at a sliver of red light leaking through the box seam. The light was steadier than before, like a droplet of congealed blood, drifting gently toward the roadside locust tree.

"It knows the way," Zhao Jianguo whispered.

"What?" Jia Dongxu leaned in.

"Don't touch," Zhao Jianguo raised his hand to block him, pulled the box closer to his chest, "this thing doesn't want to hide; it wants to be seen."

They didn't continue forward. Zhao Jianguo squatted, untied the rope, and opened a corner of the tool box. A disc lay quietly on the cotton cloth, its surface a dim red flicker, the central pinhole breathing in a faint pulse of light and dark. He stared for a few seconds, then reached into his pocket— the system sign‑in card was still there, but a small bottle of ink had come out as well, the "invisible ink" obtained from yesterday's sign‑in, labeled "UV development, wear‑resistant".

He stared at the bottle, his mind racing.

Early the next morning, the factory buzzed with news: someone was offering a high price for "college entrance exam preview papers", claiming they were urgently needed by officials' children from outside the capital, five thousand yuan per roll, cash on the spot.

This was "inadvertently" said by Jia Dongxu while he was getting a Meal Ticket in the cafeteria, his voice not small, three tables ahead and behind heard it. He carried his bowl out, glanced back at the corner of the wall—Zhao Jianguo was squatting by his bike fixing the chain, head down, but his mouth twitched.

That evening, Zhao Jianguo sat under a lamp, spread out a forged answer sheet. He unscrewed the invisible ink bottle, dipped the pen tip in a drop, and wrote four characters on the paper: "Thieves of papers die". The strokes were heavily pressed, each line edged, like the handwritten style in police notices. After drying, the paper was as clean as before, leaving nothing.

He slipped the paper into a stack of ordinary test papers, placed it in a kraft paper bag, sealed it, leaving a faint fingerprint on the seal edge, as if someone had hurriedly opened and re‑stuck it.

On the third evening, a few furtive figures appeared outside the abandoned warehouse of the grain depot. Wind poured in through broken windows, rattling newspapers in the corners. The middleman wore an old military coat, hunched his neck, and stood at the doorway watching.

Zhao Jianguo hid on the opposite rooftop, lying on a tile, a small mirror clenched in his hand. He adjusted the angle, letting moonlight slant into the warehouse wall—there he had previously nailed three reflective mirrors, so once the light source was in place, the wall became the perfect Projection screen.

After less than ten minutes, a Tablet cart creaked up. Sitting in it was Xu Da Mao, his hat brim pulled low, clutching a Cloth Bundle in his arms. He didn't get out, but nodded at the middleman, who immediately handed over a bulging canvas sack.

At the moment the Cloth Bundle was exchanged, Zhao Jianguo tapped the tile three times with his finger.

The warehouse door was kicked open violently, three plainclothes officers rushed in, movements crisp; one lunged at the middleman, the other two quickly secured the exit. The team leader flashed his credentials, voice low but clear: "City bureau is handling the case, please cooperate with the investigation."

Xu Da Mao's complexion changed, he turned to jump off the cart. But before he steadied himself, a "snap" sounded, and the portable UV Lamp lit up.

The light swept over the forged test paper, and in an instant, the wall projected a blinding red glow—"Thieves of papers die" loomed in large characters, strokes heavy, as if written in blood.

The entire warehouse fell silent.

Xu Da Mao stared, lips trembling: "This... this can't be!"

"Why not?" Zhao Jianguo walked in from the doorway, holding an empty ink bottle, "You sell fake answers, I give you a warning, fair trade."

Xu Da Mao snapped his head up, eyes blazing: "You? When did you act?"

"The first time you stole an admission ticket," Zhao Jianguo slipped the bottle back into his pocket, "Every time you reach out, I make a note."

Xu Da Mao gritted his teeth, lunged at him, both hands clawing at his face. Zhao Jianguo sidestepped, movement crisp, his shoe sole slipped, landing squarely on a metallic object that had fallen to the ground.

He looked down: it was a pocket watch, silver case, the back engraved with a line of tiny characters, unreadable, but its style clearly not domestically made.

"Yo, still bringing foreign goods?" Zhao Jianguo bent to pick it up, held it in his palm, "Last time it was an admission ticket, this time a watch; every time you commit a crime, you leave a souvenir."

Xu Da Mao's face flushed to a pork‑liver hue, pointing at him, speechless.

The police officer stepped forward to examine the pocket watch, opened the case back; inside, the movement was complex, the Gear Set arrangement abnormal, unlike any common watch. The team leader frowned: "This isn't an ordinary watch; it's a signal‑trigger device."

"I told you so," Zhao Jianguo nodded, "He dares to trade here, meaning someone is watching from behind. This watch is probably a remote transaction confirmation 'receipt device'."

The police placed the watch into an evidence bag, then lifted the developed test paper to photograph and archive it. Xu Da Mao, restrained by both arms, kept struggling: "You can't arrest me! I'm just the middleman! Someone sent it to me!"

"Who sent you?" the team leader asked.

"I... I don't know!" Xu Da Mao's voice trembled, "It was a call in the middle of the night, saying if I leave the goods properly, I'd get money!"

"Then why did you have to come yourself?" Zhao Jianguo interjected, "Can't you send a subordinate? Or you don't trust anyone else handling it?"

Xu Da Mao stayed silent, his gaze wandering.

Zhao Jianguo smiled, waved the ink bottle, "Do you know why I chose this ink? Because it leaves no trace, only a specific light can reveal it. It's like some people's deeds—unseen normally, but exposed the moment they're illuminated."

The police officer patted his shoulder: "Comrade, thank you for the tip. This case involves overseas communication channels; we will investigate thoroughly."

"The thanks go to you," Zhao Jianguo slipped his hand into his pocket, "If you hadn't arrived in time, I was afraid the red characters wouldn't be bright enough."

The words barely left his mouth when a police siren sounded in the distance. A police car slowly drove into the alley, its lights sweeping the warehouse's outer wall, making the four red characters even more conspicuous.

Before Xu Da Mao was forced into the car, he suddenly turned his head toward Zhao Jianguo, hoarse voice: "You think that's it? They won't stop."

"I know," Zhao Jianguo said, looking at him, "But each time they move, I make a note. One day, the ledger will turn against them."

The police car doors closed, its taillights lit, slowly disappearing around the corner.

Only Zhao Jianguo and a few police remained on the scene. A young officer was taking a statement: "Please tell us again, how did you discover the problem with this test paper?"

Zhao Jianguo was about to speak when he felt the sign‑in card in his pocket give a slight tremor.

He calmly pulled out the card, glanced under the streetlamp—on the Screen a new prompt flashed:

【Detected unregistered temporal‑spatial beacon residual signal, source: City West Suburb No. 7 Courtyard】

He paused, slipped the card back, looked up and asked: "That pocket watch, can I have another look?"

The officer hesitated: "Not now, it's already sealed."

"Understood," Zhao Jianguo nodded, "But I suggest a prompt frequency‑band analysis. That thing isn't just a watch; it can receive commands."

The other noted the remark, closed the notebook: "We will handle it."

Zhao Jianguo stood where he was, the night wind pressing his clothes to his back. He looked down at his right hand; the lingering heat in his palm hadn't faded.

He flexed his fingers, turned and walked toward the bike.

As soon as he grasped the handlebars, the card in his pocket trembled again.

This time there was no text, only a slender red line appearing at the edge of the Screen, like a cut, slowly extending upward.