As rainwater seeped in through the cracks in the door, Chen Hao was piling the last bag of sand over the gap in the south gate. His shoes were long since worn out, and his toes were sticking out of the holes, slipping and sliding on the wet ground.

"It's blocked!" he gasped. "At least it can hold for a while longer."

Carl wiped the water from his face; the abrasion on his forehead was still bleeding. He ignored it, staring at the rising water level outside the door. "If this rain continues for another two hours, we'll have to swim in."

"Don't jinx it." Chen Hao kicked the drain pump switch by the door. The machine hummed and started pumping water out. But the water output was clearly not keeping up with the water intake, and the floor was already half a foot deep with muddy water.

Nana stood in front of the control panel, her indicator lights flashing rapidly. "The water level in storage room number three is continuously rising, and cracks have appeared in the outer wall of the main circuit room. The leakage rate is increasing by 4.7 liters per minute."

"Susan!" Chen Hao turned and shouted, "Has the backup power been switched off?"

“Just shut it off.” Susan leaned against the wall, still clutching her insulated gloves. Her face was pale, her lips trembled slightly, but her voice was steady. “The main power line was disconnected, and we’re currently using underground battery packs for power.”

"Okay." Chen Hao nodded. "How long will the battery last?"

“Theoretically, it will last forty-eight hours,” Nana said. “But if the pumps and monitoring system are running at full capacity, it will last for a maximum of twenty hours.”

"Then we'll use it sparingly." Chen Hao took off his coat, wrung out some water, and tossed it aside. "Save lives first, then save the equipment. The order can't be reversed."

After he finished speaking, he walked towards the storage room and stepped into the knee-deep water. The water was icy cold and mixed with mud, making his feet numb. He bent down and touched the floating sealed boxes, finding that the bottom row had begun to loosen.

“These instruments can’t be soaked,” he said. “They need to be moved immediately.”

Susan followed them in and saw the shelves submerged in water. She gritted her teeth and said, "Move the lighter ones first, and use the casters for the heavier ones."

"You can still move?" Chen Hao asked.

"I won't die," she said. "As long as they don't let me climb too high."

Chen Hao grinned, "Okay, then you take charge of paving the transport route, and I'll handle the heavy lifting."

He bent down to pick up a metal box, and as soon as he lifted it, his right arm throbbed. The pain of a muscle strain shot straight to his head, but he didn't let go. He stubbornly pushed it onto his shoulder and walked step by step uphill.

Carl then entered the house and, seeing the two men busy at work, rolled up his trousers without a word and waded into the water. "I'll go get some canvas and build a makeshift platform."

“The foundation of the east wall is slightly higher,” Nana suddenly said. “It can be used as a temporary distribution point for supplies.”

"How did you know?" Carl turned around.

“Retrieve the building structure drawings,” she said. “The original design marked this area as a flood buffer zone.”

"You still keep this kind of thing?" Chen Hao asked, panting as he put the box down.

“All base data is archived in the database,” Nana said calmly, “including what happened last week when you secretly changed the angle of the surveillance cameras.”

"Hey!" Chen Hao glared, "That's because I don't want to be caught secretly eating compressed biscuits!"

“The records show that you ate three times in total,” Nana said. “The last time was at 2:17 a.m., and the chewing frequency was abnormal, which may be due to indigestion.”

Carl laughed out loud, "You still remember your eating habits?"

“Health data affects the team’s survival rate,” Nana said. “I suggest Chen Hao reduce his nighttime meals to avoid sudden gastrointestinal problems that could affect mission execution.”

"Right now, I just want to stop being hungry." Chen Hao rubbed his right arm. "Once this is over, I'm going to eat hot pot for three days straight."

"As long as the base doesn't become a fishpond." Carl came back carrying a canvas, spread it on the ground, and said, "Come on, lend a hand."

The three of them worked together to secure the canvas between several metal frames, creating a passageway above the water. Susan sat on the side, placing the small pieces of equipment on it one by one.

Nana stood in front of the control panel, water dripping from the casing, her right leg making a slight scraping sound. She didn't mention any malfunction, but the scanning motion was a beat slower than usual.

"How's it going on your end?" Chen Hao asked.

“The power system is stable,” she said, “but the roof drainpipes are clogged and water is backflowing.”

Which location?

"Above the corridor in Zone B."

Chen Hao looked up at the ceiling. "That's the closest to the control room. We can't delay."

He turned to look for his toolbox, finding a long pole and a cleaning hook. Just as he was about to climb the ladder, Susan stopped him.

"Your arm is injured, don't push yourself."

"If I don't go, who will?" Chen Hao said. "You know how to fix pipes?"

“I will,” Nana said.

Everyone was stunned.

"Can you fix it?" Chen Hao asked.

“The knowledge base contains basic repair skills,” she said. “There are detailed procedures for dredging, welding, and electrical rewiring.”

"Then why didn't you say so earlier?"

“Nobody asks,” she said.

Chen Hao opened his mouth, but in the end only managed to utter one sentence: "It's really deadly for robots to talk about logic."

Nana took the tools, her movements as she climbed the ladder somewhat hesitantly. The strange noise from her right leg became more pronounced, but she stood firmly and reached in to insert the cleaning hook into the drain.

A few minutes later, a clump of blackened, rotten leaves was pulled out.

“The blockage has been cleared,” she said. “Water flow has resumed.”

Sure enough, the sound of water on the ceiling subsided.

"Wow, that's awesome!" Carl clapped his hands. "We'll call you every time our pipes break from now on."

"On the condition that you pay for the repairs," Chen Hao joked. "It's calculated by the hour, plus the cost of materials."

“The fee has been added to your personal debt list,” Nana said. “Currently, you owe the base a total of 237 yuan in material compensation.”

"What?" Chen Hao's eyes widened. "When did I start owing so much?"

"Three packs of compressed biscuits, two energy bars, plus an extra battery I used last night," she said. "Everything is recorded."

Carl laughed so hard he couldn't stand up straight. "You even remembered this?"

“Disorganized management leads to resource shortages,” Nana said. “The last time the food got moldy was a lesson learned.”

The atmosphere suddenly became a bit somber.

Chen Hao looked down at his soaked clothes, then at the boxes he hadn't finished moving on the ground, and sighed, "Alright, once this is over, I'll voluntarily report every single bite I ate."

“I suggest we do it immediately,” Nana said. “We can register now.”

"Now?" Chen Hao smiled wryly. "My brain is completely full of water right now, I can't remember what I ate at all."

“Based on your behavioral patterns, your calorie intake today is about 123 percent of the standard value,” Nana said. “The excess mainly comes from wild berries and half a compressed biscuit.”

"You're still making calculations?" Chen Hao shook his head. "Are you a robot or a nutritionist?"

“Yes, all of them,” she said.

After a two-second silence, everyone suddenly burst into laughter.

The laughter was brief, but genuine.

The rain was still falling outside, the water pump was humming, and the water level had temporarily stabilized. Chen Hao wiped his face and tightened his belt again. "Let's get back to work after we've finished laughing. Nobody gets a break until the equipment is moved."

They went back into the water.

Chen Hao carried the boxes back and forth, his arms growing heavier and his breathing becoming more labored. But he didn't stop until the last sealed box was pushed onto the platform.

Susan checked all the equipment interfaces and confirmed that there were no signs of water ingress.

Carl repacked the sandbags and then covered the gap in the doorway with a plastic sheet.

Nana stayed at the control panel, updating all the data in real time.

"The leakage in the main circuit room has slowed down," she said. "The water level in storage room number three is dropping."

"Finally, things are stable." Chen Hao sat down against the wall, his clothes still dripping wet. "What's next?"

“Wait for the rain to stop,” Nana said, “and at the same time, repair the lubrication system on my right leg.”

"You're only telling me now?" Chen Hao looked up. "Your leg has been acting strangely for a while now."

“It won’t affect mobility,” she said, “but prolonged wading could cause joints to become stuck.”

"Then why don't you hurry up and fix it?"

“A dry environment and specialized oils are needed,” she said. “Currently, these conditions are not met.”

Chen Hao thought for a moment, then got up, found a heater, plugged it in, and turned it on.

"It'll do," he said. "At least it can dry the water."

Nana stood in front of the hot air, and the water droplets on the outer casing slowly evaporated. She slightly raised her right leg, revealing a small maintenance opening at the bottom.

Chen Hao squatted down and took a look. "How do you open this thing?"

“Spin it counterclockwise eight times,” she said.

He did as instructed, unscrewed the cap, and inside was a gear covered in mud.

“It’s dirty,” he said.

"Just apply lubricant after cleaning," she said. "The lubricant is in the third compartment of the toolbox."

Chen Hao brought over a bottle of silver liquid and carefully poured it in. The gears turned a few times, then clicked and returned to normal.

"All done?" he asked.

"System self-check in progress," she said.

The indicator light flashed a few times.

"Lubrication efficiency has recovered to 89 percent," she said. "The mission can continue."

"Eighty-nine is fine too," Chen Hao stood up. "It's better than getting stuck."

He had just finished speaking when a muffled thud came from above.

It sounded like something heavy had hit the roof.

Everyone looked up.

“An abnormal roof load-bearing capacity has been detected,” Nana said immediately. “The structural stress in zone B exceeds the threshold.”

"Is the water too thick?" Susan asked.

“There’s a 76 percent chance,” Nana said. “I suggest sending someone to check it out immediately.”

Chen Hao grabbed the flashlight. "I'll go."

“You just finished moving things,” Susan said. “Let someone else do it.”

"Nobody's as fat as me," Chen Hao said. "I can keep it down."

After he finished speaking, he walked towards the stairs.

No one else stopped him.

As soon as the door on the roof was pushed open, wind and rain rushed in. Chen Hao squinted and walked forward, his flashlight beam sweeping across the edge of the roof, where he found a thick layer of rotten leaves and broken branches piled up near the drain.

The water accumulated there, gathering more and more.

He walked over and used his hands to clear away the debris.

Underneath a wooden board, half of a broken metal support was stuck.