Chen Hao took the pen off his ear and casually stuffed it into his pocket. The paper was still stuck to the wall; the handwriting was a little crooked, but still legible. He glanced at Nana's screen; the data was still scrolling, seemingly endless.

“Just writing it down isn’t enough,” he said. “It needs to be changed.”

Susan looked up, her notebook still open, pen between her fingers. She didn't speak, waiting for what she would say next.

Carl leaned against the wall, his right leg crossed, his toes dangling slightly. He glanced at Chen Hao: "Again?"

“This isn’t the beginning.” Chen Hao walked to the monitoring console and tapped the table twice with his fingers. “It’s a continuation. Just because we survived this time doesn’t mean we can be so lucky next time.”

Nana's screen paused for a moment, and a new window popped up. The title was "Defense Capability Assessment Model".

"The base's current overall disaster resistance level is Level D," she said. "It can withstand conventional winds of up to level 11 and rainfall of up to 50 millimeters per hour. The peak value of this typhoon exceeds the standard by three times."

"So, we were just lucky?" Susan asked.

“Not entirely,” Nana said. “The efficiency of personnel collaboration has improved, and the average emergency response time has been shortened by 47 minutes. However, insufficient hardware support remains a fatal weakness.”

Chen Hao nodded: "See, the robot doesn't lie. We fought tooth and nail, and we still almost had the roof blown off. What about next time? If the wind is stronger and the rain is heavier, who will hold it up?"

“No one can hold them off,” Carl said. “Unless we can bury the entire base underground.”

"Then we might as well just live in a cellar," Chen Hao laughed. "The problem is, we can only repair and patch things up in the existing place. We'll add things little by little and get stronger bit by bit."

"What do you want to do first?" Susan asked.

“A wall,” Chen Hao said. “Last time the water rushed in because there was no barrier outside. The sandbags were just a makeshift pile, and they crumbled as soon as they got soaked. We need something that can really stop it.”

“A concrete wall?” Susan frowned. “We don’t have enough material.”

"Plug in sheet metal and support frames," Chen Hao gestured. "First, fence off the main area. The door needs to be lockable and at least two meters high. People can't get in, and it'll be difficult to flood in."

"What about the beasts?" Karl suddenly asked. "Have you ever considered that, besides natural disasters, something else might come?"

“Yes,” Nana said. “Infrared monitoring records show that three large mobile heat sources have appeared around the base in the past thirty days. The closest one was 800 meters away and did not get close.”

"Animals?" Susan asked.

“It’s uncertain,” Nana said. “It’s close in size to an adult brown bear, but its movement is in a straight line and it doesn’t show any foraging behavior. We can’t rule out the possibility of human intervention.”

The air went still for a moment.

"People?" Chen Hao raised an eyebrow. "There are still people in this godforsaken place?"

"We can't rule it out," Nana said.

“Then we need to build a wall even more.” Carl sat up straight. “Whether it’s wind, rain, or anything else, at least we’ll have a border.”

“The problem is, how do we build it?” Susan opened her notebook. “How many metal plates do we have available right now?”

Nana pulled up the list: "Twenty-three complete iron sheets, all the same size, two meters long and one meter wide. One hundred and seventy-six bolts in stock, of which one hundred and fifty-two are usable. Welding equipment is still available, but only half a gas canister remains."

“Not enough.” Chen Hao shook his head. “The wall needs at least sixty sheets of iron, and we also need to build a foundation. Otherwise, it will fly away like a kite in the wind.”

“We can recycle the waste,” Nana said. “During the last cleanup, we found six I-beams in the collapsed building on the east side, which were not completely rusted. There were also some exposed steel bars in the warehouse ruins on the west side.”

"Can we use it right away after we dig it up?" Carl asked.

"It needs to be cut, straightened, and rust-proofed," Nana said. "I can provide operational guidance."

“It sounds like it’ll take a month,” Carl sighed.

“It’s better than doing nothing,” Chen Hao said. “We can’t wait until all the conditions are perfect before we start. We’ll use what we have now. We’ll work as we go and look for more.”

“There’s another problem,” Susan said, “the security system. Even if the wall is built, how will we know if anyone is approaching from the outside? Relying on Nana getting up in the middle of the night to check the screen?”

“We can set up an alarm,” Nana said. “Using existing vibration sensors, we can deploy them at key points along the perimeter of the wall. Once an abnormal contact is detected, a buzzer will be triggered.”

Is the power supply sufficient?

“It can be connected to a backup battery pack,” Nana said. “Currently, the battery can sustain continuous operation for 72 hours.”

"With the progress of the solar panel repairs, we expect to restore charging functionality in three days," Chen Hao said. "That should be enough to last for one round of replacements."

"Wait a minute." Karl raised his hand. "Have you forgotten something?"

"What?"

“People,” Carl said. “The four of us have to repair the roof, clear the rubble, build walls, install alarms, and take turns on duty. Who gets to rest? Who eats? Who doesn’t want to lie still?”

No one spoke.

Chen Hao rubbed his stomach: "I am indeed tired. But I slept for six hours last night, didn't dream, and the first thing I wanted to do when I woke up was to drink porridge. It means my body can still hold up."

“I’m not talking about physical strength,” Carl said. “I’m talking about the lack of prioritization. Everything is important, which is the same as nothing being important. In the end, we just run around in a chaotic mess and do nothing well.”

“He’s right,” Susan nodded. “We need a plan. Not ‘do this first, then do that,’ but to clearly define—what we should do right now.”

Nana's screen flashed, and a new interface popped up.

"I recommend initiating a defense system planning process," she said. "Based on existing resources and threat assessments, a phased construction plan should be generated, divided into three phases."

"Which three episodes?" Chen Hao asked.

"Phase 1: Basic protection. This includes building a perimeter wall, deploying a security system, and upgrading the waterproofing of the core area. Objective: To achieve physical isolation and initial early warning."

Phase II: Structural reinforcement. Reinforce the load-bearing structure of the main hall, add flood prevention devices for ventilation openings in the underground storage rooms, and rebuild the roof drainage system. Objective: Improve building stability.

Phase Three: Proactive Defense. Explore the construction of remote monitoring towers, test the feasibility of simplified power grids, and establish an external patrol mechanism. Objective: Expand the scope of security control.

After he finished speaking, a table appeared on the screen, with the time, materials, and manpower requirements all marked.

Chen Hao stared at it for half a minute: "Since when can you even calculate this?"

“There are 372 similar base defense cases in the database,” Nana said. “We selected the optimal template by combining local environmental parameters.”

“It sounds like a regular army battle,” Carl said. “But we’re just four scavengers.”

"Precisely because we're scavengers," Chen Hao laughed, "we need to follow the rules even more. Otherwise, we'll be exhausted before the wind even blows next time."

Susan closed her notebook: "I support phased implementation. But the problem now is that the first phase will take at least ten days. What if there's extreme weather during that time?"

“There won’t be a second typhoon,” Nana said. “Weather models predict that no major storms will form in the next fifteen days.”

Are you sure?

“It’s uncertain,” Nana said, “but based on cloud movement trends, air pressure change curves, and ocean temperature distribution, the probability is less than 3.2 percent.”

“That means there’s still a possibility,” Carl said.

"So we have to speed things up," Chen Hao said. "Ten days is too long. The wall must be completed within seven days. The security system will be installed simultaneously. Roof repairs can be postponed, but the materials must be ready by the third day."

"How should we divide the manpower?" Susan asked.

“Karl and I will be in charge of moving and assembling,” Chen Hao said. “You and Nana will oversee the design and wiring. We’ll meet twice a day, morning and evening, to check on the progress.”

“I have a condition,” Carl suddenly said.

"you say."

"After this is over, I need to get a full twelve hours of sleep," he said. "No waking up, no alarms, and no saying 'there's a bear outside.'"

"Okay," Chen Hao laughed, "as long as you don't sleepwalk and tear down the wall."

Susan scribbled a few words in her notebook, then looked up: "There's one more thing. We keep talking about 'defense,' but what are we defending against? The weather? Wild animals? Or... people?"

No one answered.

Nana's screen was lit up, and the map showed the three heat sources, arranged in a triangle around the base.

"We cannot determine their intentions at this time," she said, "but based on their movement patterns, we cannot rule out the possibility of reconnaissance."

"Does that mean someone is watching us?" Susan asked in a lower voice.

“I can’t confirm,” Nana said, “but I recommend raising the nighttime alert level.”

Chen Hao stood in front of the monitoring console, his fingers slowly tapping the table. The rhythm was slow, one tap after another.

“Then we need to hurry,” he said. “No matter who’s out there, we can’t let them think we’re easy to bully.”

He turned around, picked up a pen, and then took a flashlight out of his pocket and shone it on the wall.

The paper with the title "Typhoon Response Summary" is still there.

He tore it off, folded it in half, and stuffed it into his breast pocket.

“From today onward,” he said, “we are not just people who repair houses.”

"We are the ones who build fortresses."

Carl glanced at him: "When did you become so serious?"

“I’ve always been serious,” Chen Hao said. “I just used to be serious about being lazy.”

Susan smiled, but quickly stopped.

Nana has started printing the materials list. The printer hums, spitting out sheets of paper one by one.

Chen Hao walked over and picked up the first one.

The document above reads: **Phase I Project Material Allocation Table**.

He flipped it over and found it was an old blueprint, depicting some kind of architectural structure, with blurry words printed in the corner: **Seventh Research Station - Prototype of Peripheral Protection**.

He stared at it for two seconds.

"Nana," he said, "where did you get this picture?"

“It comes with random matching from the database,” Nana said. “Number A-739, marked as an abandoned project.”

"Abandoned?" Chen Hao traced the words with his finger. "Why?"

“The record is missing,” Nana said. “There’s only one note.”

Chen Hao looked down.

The last line of small print on the paper was so faintly printed that it was almost illegible:

"On the day of completion, everyone went missing."