Before the morning fog had even lifted, Chen Hao had already rolled up the waterproof tarp and stuffed it into his backpack. He squatted down to check the trailer wheels, giving them a couple of hard tugs.

"Can this thing really hold up?"

Nana stood beside her, swiping her finger across the tablet screen: "The load calculation shows that transporting twenty standard boards is no problem."

Susan walked over with her bag slung over her shoulder, glanced at the trailer, and asked, "Isn't Carl coming?"

“He said the fuel line can’t be shut down.” Chen Hao stood up and clapped his hands. “Just the three of us, we can go in lightly equipped.”

Nana put away her equipment: "The route has been confirmed. It's 3.2 kilometers to the northwest. It's estimated to take 50 minutes to walk to the target area."

The sun was just rising when the three set off. They didn't talk much on the way, with Chen Hao glancing back at the tow truck every now and then, worried that it might fall apart halfway through the journey.

When we arrived, the greenhouse was more intact than we had imagined. Although half of the roof had collapsed, the south-facing rows of planks were almost undamaged, and the iron frame was still sturdy.

"Luckily, it didn't turn brittle." Chen Hao reached out and touched a piece of board.

Susan circled around and said, "Nobody's here."

Nana scanned the surroundings: "No heat source signal detected, and limited recent activity."

Chen Hao grinned: "Freebies always taste the best."

They had just loaded the first plank onto the trailer when five people emerged from behind the rubble on the side.

The leader was a tall, thin man carrying a steel pipe. Behind him were four men and women carrying sticks, wrenches, and one of them was carrying a bow and arrows.

"Stop," the tall, thin man said. "This land is under our jurisdiction."

Chen Hao put down the board and raised his hands: "We're just taking some scrap."

"Scrap?" the man sneered. "You call this scrap? We've been guarding this place for three months. Anyone who tries to touch it will have to pay the price."

Susan took half a step forward: "What's the price?"

"Three times the labor, or equivalent energy."

“We don’t have any extra manpower,” Chen Hao said, “and we don’t have any extra fuel for you either.”

"Then you'll go back empty-handed."

The atmosphere froze. Wind blew in from the dilapidated roof, making the plastic sheets rattle.

Chen Hao lowered his head and pondered. The other side had five people, poorly equipped but outnumbered, so a direct confrontation was definitely not an option.

He suddenly looked up: "Do you know about tunnels?"

The other party was taken aback.

“We built an underground tunnel, 15 meters deep and more than 500 meters long.” Chen Hao took out a waterproof tarpaulin and spread it out, on which a simple diagram was drawn. “It has a ventilation system, a support structure, and it is also explosion-proof.”

The tall, thin man frowned: "Are you bragging?"

Nana stepped forward and opened her tablet. The screen displayed construction records of the base's perimeter wall, the process of laying alarm circuits, and live footage of laser cutting through rock strata.

“This is our routine construction process,” she said. “The material reuse rate is 89 percent.”

Susan added, "We also achieved continuous power supply at night, using a combination of plant fermentation and solar power."

The group of people leaned closer to look at the screen, and their expressions changed.

The tall, thin man stared at the cross-sectional diagram of the tunnel: "You... really dug this deep?"

"We'll be able to reach the safe zone tomorrow," Chen Hao said. "We need to upgrade the doors and windows now to improve living efficiency. These boards are very important to us."

The two looked at each other.

A woman said in a low voice, "The windows in our warehouse were blown down by the wind last week."

The tall, thin man was silent for a few seconds: "You take ten boards, but you have to replace the rest."

"Change what?"

"Help us repair two doors and reinforce a section of wall."

Chen Hao laughed: "Sure, once we finish here, we'll send people over to help."

"You have to agree now."

“I promise you in my capacity as the person in charge,” Chen Hao said, extending his hand. “I will bring your people to visit later, and we can share the technical details.”

The tall, thin man hesitated for a moment before shaking hands.

After the deal was finalized, the other party offered to help move the materials. They pointed to a broken wall on the north side and said that was the most urgent spot, so Chen Hao noted down the location.

Before leaving, the tall, thin man asked in a low voice, "Aren't you afraid we'll follow you to the base?"

"What are you afraid of?" Chen Hao slung his bag over his shoulder. "It's not like we're stealing anything. You're welcome to come over; just bring your tools."

The group pushed their fully loaded trailer back home. As the sun rose high overhead, their shadows shrank to a ball at their feet.

Chen Hao started humming a song on the way.

“You actually dared to agree to help them repair the wall,” Susan said.

"It's nothing," Chen Hao waved his hand. "It'll be a quick thing once the window is fixed."

As Nana walked, she pulled up the data: "The thickness of the ten polycarbonate boards meets the standard, the metal bracket can be disassembled and reassembled, and the sealing solution can be optimized."

"We can hold a meeting tonight to finalize the details."

As we approached the base, we saw Karl standing at the entrance, looking around.

He ran over: "Smoothly?"

"We brought them all back." Chen Hao patted the trailer. "We also negotiated a cooperation project."

Carl gripped the handlebars, looking at the pile of materials: "You guys are quick."

“It’s not that they’re unreasonable,” Chen Hao laughed. “They’re just short of resources, and they’ve been holding back for so long that they’ve become a bit ruthless.”

Susan jumped down the slope: "I'll go check the boards and see if there are any hidden cracks."

Nana starts the scanner: "Do you need me to create a file for the materials simultaneously?"

"Of course." Chen Hao handed the waterproof cloth to Karl. "Save it and send it to the group chat. We'll use it for the meeting tonight."

Carl rummaged through the pile of materials: "This board is better than I expected."

“That’s right.” Chen Hao walked to the entrance of the main hall and looked at the old window that was still letting in drafts. “By this time tomorrow, I’m going to warm up this house.”

Nana began entering the data. Various parameters scrolled across the screen: wind pressure resistance rating, light transmittance, thermal conductivity...

Susan inspected each piece of board and found that the third piece had a slight layering on its edge. She marked it and set it aside.

Carl removed a section of the iron frame to measure: "This can be converted into a slide rail, as long as the joint is ground smooth."

Chen Hao squatted on the ground to draw a sketch, using pebbles to create the structure of the window frame.

“The double-layered structure has a gap in the middle for air insulation,” he muttered to himself. “And add a simple latch to prevent it from being blown open by the wind.”

Nana looked up: "I suggest testing alternative sealing strips first. The existing rubber is failing, so we need to find an elastic material."

What about that soft plastic behind the billboard?

"It has some flexibility, but its long-term stability is unknown."

"Let's give it a try." Chen Hao stood up. "We already have the materials, so even if we fail, it won't be a loss."

Susan came over and handed him a bottle of water: "How do you plan to divide the work?"

“You’ll be in charge of material allocation, Carl will be in charge of processing, Nana will provide the blueprints, and I’ll lead the installation team.”

"Shall we do it tonight?"

“We can find time during the day.” Chen Hao unscrewed the bottle cap. “The tunnel construction is progressing steadily, so there’s no need to squeeze everything in at night.”

Carl carried the iron frame toward the workshop: "I'll try to bend it into an arc first."

Susan followed up: "Remember to keep spare parts, the first batch might not be successful."

Nana continued scanning the last board. She paused after the data appeared.

"An anomaly detected."

Chen Hao leaned closer: "What's wrong?"

"The inner layer of this board has markings indicating that it may have come with an original UV-resistant coating."

Is it useful?

"It can improve weather resistance and slow down the aging process."

"That's good stuff."

"It is recommended to use it primarily for south-facing windows in the main hall."

"I'll listen to you."

As dusk approached, all materials were inventoried. Ten planks were put into storage, three complete iron frames were sent to the workshop, and the remaining scraps were sorted and stacked.

Chen Hao stood at the entrance of the main hall, looking at the new materials piled up on the open ground.

The wind seeped in through the cracks in the old window, ruffling the sweat-dampened hair on his forehead.

He turned and went into the house, pulling an old ruler from the bottom of his toolbox.

Nana followed her in: "Do you need me to recalibrate the size?"

"No need." Chen Hao gestured towards the window frame. "The old method is the safest."

He placed the ruler on the wooden table and began to draw the first line.

The pen tip made a scratching sound as it glided across the paper.

Outside, Susan was directing people to move the last basket of scraps into the warehouse.

Karl was banging on the iron frame in the workshop, and sparks flew onto the concrete floor and were extinguished instantly.

Nana stood next to Chen Hao and watched him finish drawing the window pane divisions.

“The proportions are correct,” she said.

Chen Hao put down his pen: "We'll start work tomorrow."

He picked up the blueprints, walked to the wall, and nailed them to the bulletin board.

A line of chalk writing quickly appeared below: **Initial Goal—Close the doors and windows of the main hall and dormitory area**

Chen Hao took two steps back, looked at it, and nodded.

Nana opened her terminal to record a summary of today's activities.

Chen Hao suddenly said, "By the way, weld the slide rail first tomorrow morning, and the slot must be formed in one go."

"It has been listed as a priority task."

Neither of them noticed that a piece of broken plastic was being blown around by the wind on the ground outside the door, and then it hit the threshold and stopped.