After the ticking sound came from the doorway, no one moved inside.

The scanner's red dot flashed briefly, then went out. Nana stared at the screen for five seconds, then reached out and turned off the alarm system. "It's just a delayed response from the backup battery," she said. "No intrusion."

Chen Hao released his hand from the edge of the table, his knuckles slightly white. He didn't speak, but looked down at the marks he had made, then slowly withdrew his hand and put it in his pocket.

Daylight had broken. Sunlight streamed in through the cracks in the roof, illuminating the blue crystal. It still lay quietly on the table, like an unwanted stone, but everyone knew it wasn't.

Carl sat up all night, leaning against the wall, his notebook spread out on his lap. He turned to a page covered in symbols, dotted one of the designs with the tip of his pen, then crossed it out. Susan leaned against the other wall, the knife still in her hand, but she had taken out the scabbard, though she hadn't sheathed it.

Nana walked to the control panel and tapped a few keys on the keyboard. The projector hummed, and a site plan appeared. The plan was old, with burn marks on the edges and scribbled labels.

“We need to decide on our next step,” she said.

Everyone looked up.

Chen Hao yawned and stood up to stretch his shoulders. His back cracked twice, making him wince in pain. "I said, can we fix the roof first? It rained last night, and the kettle by my bedside was half full."

“You won’t get water if you don’t sleep on the floor,” Susan said.

"I'm worried that the floorboards will get soaked and ruin the overall structural stability!" Chen Hao immediately retorted. "That's called caring about public property!"

Carl ignored him, looking at the diagram on the projector. "The materials are enough to build a 20-square-meter extension area. The question is how to use them."

"Of course it's for living in!" Chen Hao slammed his hand on the table. "I don't even have a private space to change clothes, I have to check the weather to take a shower, and I have to make sure my bed is leaky. Aren't we supposed to be fleeing a disaster? How come we're getting more and more backward?"

“We brought back technology,” Carl said, opening his notebook. “Not a renovation list. These symbols can convert energy, and if we understand the principles, we can achieve stable power supply, automatic purification, and environmental control—that’s the key to survival.”

"Then you should at least build me a roof that doesn't leak before talking about the fundamentals," Chen Hao rolled his eyes. "What I need most right now is dry underwear."

Susan couldn't help but twitch her lips, then suppressed it.

Carl didn't laugh. "If all you think about is comfort, what's the difference between that and hiding in a cave by a fire? The things outside won't stop coming just because we're sleeping well."

"I didn't say I didn't want to do research!" Chen Hao raised his voice. "I meant we should address basic human rights issues first. Who says development means sleeping in the mud? The first rule of a civilized society is housing security!"

“Resources are limited.” Carl’s tone turned cold. “Every alloy plate, every cable, must be carefully calculated. Fragmented construction will only prevent both sides from succeeding.”

“Then let’s do it in stages!” Chen Hao waved his hand. “First, build a house to shelter you from the wind and rain, then set up your laboratory. It’s better than just daydreaming right now.”

“By the time your house is finished, the materials will be all used up.” Carl closed his notebook. “By then, you won’t even be able to fix the door, let alone the lab.”

“That’s enough, you two,” Susan suddenly said. “You’re making such a racket, it’s like a marketplace.”

Both of them shut up at the same time.

Nana remained silent. She switched the projector to the mineral analysis page and pulled up a set of data. "The existing materials support two options: one is to build living modules, including waterproofing layers, partitions, and storage systems; the other is to build research units, equipped with basic analytical equipment and energy interfaces."

She paused. "But they can't be done at the same time."

The room fell silent.

Chen Hao sat on the wooden crate, picked up a piece of gravel from the table, and rubbed it back and forth in his hands. The edge of the stone was a bit prickly, but he didn't stop.

"I never imagined I'd be arguing with someone over a roof," he said. "Back in school, I was the kind of lazy person who wouldn't even copy my homework. Now? I volunteer to do manual labor, and people still think I'm narrow-minded."

“This isn’t a matter of perspective,” Carl said. “It’s a matter of priorities.”

"Then tell me, what does 'priority' mean?" Chen Hao looked up. "Is living a long life more important, or living like a human being?"

“Without technology, no one can survive long.” Karl pointed to the crystal. “It saved us, but it won’t tell us how to use it. If we don’t hurry up and study it, the flashlight won’t be of any use next time we encounter a stronger creature.”

"So you're planning to throw everything in for this experiment?" Chen Hao sneered. "What if we research for six months and come up with nothing? Are we going to have to run around naked again?"

“At least we’re trying to break through,” Carl said, his voice lowering, “instead of being content with just ‘not leaking.’”

“That sounds really noble.” Chen Hao stood up and took two steps forward. “Then tell me, when you’re staying up all night drawing blueprints, have you ever thought about who brings you food? Who keeps watch for you? Who helps you carry the equipment back? We’re not machines. We need rest, we need a sense of security, we need a little bit of… a normal life.”

He finished speaking and took a breath.

No one responded.

Susan sheathed the knife and gently placed it on the table. She walked to the projector and ran her finger across the residential area plan. "I can take charge of reinforcing the walls," she said. "Using plant fibers mixed with concrete to improve moisture resistance and strength."

"Thank you," Chen Hao nodded.

“But I disagree with building only housing.” She turned to Carl. “We can’t just do research.”

"We'll tackle both simultaneously," she said. "We'll live there while we do our research."

"No." The two spoke almost simultaneously.

Chen Hao frowned: "The progress is too slow. What will we do when the rainy season comes?"

Carl shook his head: "When resources are scattered, efficiency drops to zero. This kind of thing must be done by concentrating efforts."

"Then let's draw lots," Chen Hao shrugged. "Whoever loses gets to decide."

“This is no child’s play,” Carl said, staring at him. “This is about deciding our future.”

“I know it’s important,” Chen Hao said in a low voice. “But I also know that if I don’t even have a dry bed right now, I’ll start to question the point of being here. I’m not a scientist, and I’m not a soldier. I just want to live, to live comfortably.”

Carl looked at him with a complicated expression.

Nana stood by the control panel, her finger hovering over the upload button. The data package was already prepared; all she had to do was press it to begin the construction preparation process. But she didn't move.

She looked at the crystal on the table. The blue light was faint, but it was definitely there.

“We used to be able to run,” she said. “Now we can build. But what to build, how to build, nobody has taught us.”

“That’s why we need to discuss this.” Chen Hao sat down and rubbed his temples. “I’m not against research. I just… don’t want to live a hard life anymore. Can the things we risked our lives to bring back make our lives a little better?”

“Getting better isn’t about sleeping more,” Carl said. “It’s about learning more.”

"Then you take control of it," Chen Hao said with a wry smile. "Once you've mastered it, remember to wake me up. Don't let me die in a leaky house."

Susan sighed. "You're all right."

"That would be even more troublesome," Chen Hao said, shrugging.

Nana finally withdrew her hand and turned off the projector. The screen went black.

“We’re not short of materials right now,” she said. “We’re afraid that if we make the wrong choice, everything else will be wrong.”

The room fell completely silent.

Chen Hao lowered his head and continued rubbing the stone. Susan leaned back against the wall, her fingers unconsciously stroking the knife handle. Carl opened his notebook, his pen hovering over a circuit diagram, hesitant to write anything.

The wind outside the window blew the tin bucket, making a clanging sound.

It was getting dark.

Not all the lights were on; only a small light source remained on the control panel. The blue crystal gleamed in the dim light, as if waiting for a decision.

Chen Hao looked up at Karl.

"You say technology determines life and death," he asked. "But if you don't even want to live, what's the point of researching?"