Chen Hao squatted by the river, his fingers touching the edge of the steel bar. The U-shaped groove was indeed pointing downwards, unlike when he had bent it.

"This thing just rolled over by itself?" He looked up at Nana. "You stepped on this spot, didn't you?"

“Yes.” Nana bowed her head. “I used it for load-bearing tests.”

“But its opening was originally facing upwards.” Chen Hao reached out and pulled out the steel bar, then straightened it again. “It won’t turn by itself if no one touches it.”

Nana didn't say anything, but the optical lens flashed.

The wind blew across the river, the water continued to flow, and the stones were gently swayed by the current.

Chen Hao stared at the stone with the steel bar inserted for two seconds, then finally pushed it back into the ground, U-shaped opening facing upwards. "Never mind, let's go," he said. "Anyway, we've crossed the bridge, and we have the stuff."

He turned and pushed the trailer, the wheels squeaking.

Nana followed beside him, her screen unfolding from her wrist as she glanced at the bottom of the trailer. "The metal sheet on the right rear side is loose. I recommend checking it at least three times during the trip."

"Can't you say something auspicious?" Chen Hao patted the car body. "I know it's not sturdy, but as long as it can move, that's fine."

They walked back the way they came. The sun was already setting, and their shadows were growing longer and longer.

Less than a hundred meters later, the trailer suddenly veered off course, and a bolt box slid off the side, hitting the ground with a dull thud.

"I knew it." Chen Hao stopped, bent down to pick up the box, "This lousy car is even less reliable than my weight loss plan."

Nana walked over and squatted down to inspect the connection. "The wire is broken, and the sheet metal has shifted five centimeters. It needs to be reinforced immediately."

"Alright then," Chen Hao sighed. "You take the tools, I'll hold them."

The two men worked for ten minutes, wrapping the wire three times and adding two more clips. Chen Hao stood up and clapped his hands: "This time we should be able to hold out until we get to the base."

"I suggest reducing your speed and avoiding sharp turns." Nana put away her toolbox.

"I'm practically a tortoise, how can I be slow?"

They continued onward. Along the way, Chen Hao stopped every so often to check the wheels and ropes. Once, he noticed a piece of sheet metal was sticking up and immediately disassembled and reassembled it.

“You used to be quite lazy,” Nana suddenly said.

“I’m not very diligent now.” Chen Hao tightened the last wire. “But I’m afraid if something gets lost, I won’t be able to explain it when I get back.”

“Karl will complain that you brought back too much.”

"Then tell him to stop picking and choosing scraps."

By the time they finally saw the outline of the base, the sky was already beginning to turn gray. Susan and Carl were standing in the open space waiting for them.

“You’re finally back,” Susan greeted them. “We thought you’d fallen into the river.”

"Almost." Chen Hao let go of the handle, leaned back, and fell onto the grass. "The river was freezing cold, and the bridge was shaking like it was going to a disco."

Carl had already rushed to the trailer. "What's this?" he asked, lifting a corner of the canvas. "Metal brackets? And so many connectors?"

“They’re all new.” Chen Hao lay still, “No rust, no deformation, and the tags are all there.”

Susan opened the top folder. "The 'Regional Geological Stability Assessment Brief'?" she looked up. "Where did you find it?"

“A warehouse that was half collapsed.” Chen Hao sat up. “The door was blocked up, and Nana squeezed in through the crack.”

“I’m not squeezing,” Nana corrected. “The crack is 38 centimeters wide, and I’m 36 centimeters tall.”

"You've even measured yourself?" Chen Hao laughed.

“All the data is in the database,” she said, “including your current body temperature and heart rate.”

"Stop." Susan closed the file. "Let's check the supplies first, then we can chat."

The four of them gathered around the trailer and began unloading. Carl was in charge of moving the heavier loads, Susan registered the items with numbers, Nana entered the data into the system, and Chen Hao directed the placement of the goods.

"Put this box on the left," he said. "That's the waiting area. Stand that stand against the wall so it doesn't fall over and hurt your feet."

Halfway through the work, Chen Hao suddenly called for a stop. "Wait." He bent down to search for the bolt box that had fallen earlier. "A pack of M8 connectors is missing."

“It might have fallen off on the way,” Susan asked. “When was the last checkup?”

"It was still there before we crossed the bridge." Chen Hao frowned. "Could it really have fallen into the river?"

“No need to go back.” Nana pulled up the records. “The last time the box was opened was fifteen minutes before arriving at the base, and all the items were intact at that time.”

“It must have been lost along this stretch of road.” Chen Hao stood up. “I’ll go take a look.”

“No need.” Nana pointed to the ground. “There are slight scratches here, pointing to the right side of the trailer. The item should be stuck in the axle clearance.”

She squatted down, brushed aside the mud with her hands, and sure enough, pulled out a small iron box from between the wheels.

"You're lucky." Chen Hao took the box. "I'd like to make another trip."

"Aren't you tired?" Carl asked, looking at him.

"I'm tired." Chen Hao put the box away. "But I don't want to find that some parts are missing when I start work tomorrow."

Everyone kept their hands busy.

As darkness fell, Nana turned on her shoulder light, which illuminated the pile of materials.

"We can begin." Chen Hao clapped his hands. "First, install the support frame for the main living quarters, three sets on each of the north and south sides."

“I’ll drill the hole,” Carl said, picking up the electric drill.

"Wait a minute." Nana scanned the wall. "There are micro-cracks below the original anchor points. Direct installation may cause it to fall off."

"Then let's move to another place," Chen Hao asked. "Where to?"

“Move it outwards by fifty centimeters,” she said, “to avoid the fault extension zone. Use an angled, cross-fixing method to improve overall stability.”

"Okay." Chen Hao drew lines on the ground with chalk. "Do as you say."

The four repositioned themselves. Chen Hao and Susan were responsible for marking the points, while Carl and Nana prepared the steel stakes.

The drill bit had just touched the wall when it clicked and stopped.

"Out of power?" Chen Hao leaned closer.

"Battery remaining at seven percent." Nana checked the interface. "External charging is required."

"You can also charge other people?"

“I can share the power interface,” she said, “but only for fifteen minutes.”

“That’s enough.” Carl plugged the drill into her spare port.

The machine restarted, and drilling continued.

While holding onto the support frame, Chen Hao shouted, "Slow down! Don't miss!"

“You’re making more noise than my drill,” Carl retorted.

The first steel pile was successfully driven in. Then came the second and the third.

Susan took the connector and tried to install it, finally aligning it with the slot after two attempts.

"How do I connect this?" she asked.

Nana raised her hand, and an assembly animation popped up on the screen. "Press the left-side button and rotate it ninety degrees to lock it."

"You should have said so earlier." Susan did as she was told, and the package was packed with a click.

“From now on, we’ll divide the work,” Chen Hao suggested. “Nana and Carl will be in one group, and you’ll handle the mechanical work. Susan and I will handle the pre-assembly and transportation.”

“Agreed,” Susan nodded.

Progress has accelerated significantly. All six sets of support structures were erected before it got completely dark, and most of the waterproof tarpaulin was laid out.

Chen Hao took a few steps back and looked around. "It looks pretty stable."

“The structural load test will be completed in two hours,” Nana said. “There is currently no abnormal data.”

"That's settled then." Carl put his tools away. "Shall we continue sealing the border tomorrow?"

“Right.” Chen Hao stretched. “Let’s get the framework sorted out first, then deal with the cracks.”

After finishing the last list, Susan looked up and asked, "Are these supports enough?"

"That's enough." Chen Hao counted the remaining materials. "We can assemble two more rooms."

"And what about the energy room?" she asked again.

"We'll decide how to reinforce it after Nana finishes analyzing the geological data," he said. "Maybe some places won't require so much effort."

Nana was half-squatting next to the equipment, updating the engineering log; the machine was slightly warm.

Chen Hao walked over and patted her on the shoulder. "You've had a hard day."

“My energy consumption is within the normal range,” she said, “but your step count is 230 percent above the daily average.”

"That's why my legs are weak right now." Chen Hao plopped down on a concrete block. "Could we find a warehouse closer next time?"

“Next time, we can choose to use drones for reconnaissance,” she said.

"You actually joked?" Chen Hao was stunned.

“I didn’t,” she said. “I was just stating possible solutions.”

"Alright then." Chen Hao shook his head with a smile. "Anyway, the stuff is back, and no one is missing."

He looked up at the sky, and the stars began to appear.

The lights in the base gradually came on, illuminating the newly installed support structures, casting shadows on the wall like a row of neat ribs.

Carl tightened the last nut and put the wrench back in the toolbox.

Susan piled the remaining materials into the makeshift storeroom and closed the door behind her.

Nana closed the light screen and stood up straight.

Chen Hao stood up, walked to the main building, and reached out to touch the newly installed scaffolding.

The metal was cold, and the weld was strong.

"Let's keep going tomorrow," he said.

A faint metallic scraping sound came from afar, like the wind blowing through sheet metal.

Chen Hao glanced back at the direction of the river.

The wind stopped.