The red light swept past Chen Hao's feet, but he didn't move.

No one spoke in the hall. The triangular beam of light that had been spinning suddenly accelerated, as if it had been pushed by something. Nana stared at the beam of light moving back and forth overhead, her fingers tapping lightly on the seam of her arm.

“It recognized us,” she said. “Not an enemy, nor an administrator. It’s… an unknown variable.”

"What do you mean?" Chen Hao asked in a low voice, "Are we exploiting a bug?"

"More or less." Nana lowered her voice. "The system is reclassifying our identities. But its internal data is incomplete, and its judgment logic is chaotic."

Susan took a half step back and leaned against a pillar: "So what are we now?"

“Temporary visitor,” Nana said. “A little higher access level than the cleaning robot, but lower than the ventilation duct maintenance worker.”

Carl almost burst out laughing: "You really dare to split it up?"

“I’m talking about the actual rating,” Nana said expressionlessly. “Its database has a seven-level access control system, and we are currently at level 6.5, which is ‘observable but not accessible’.”

Chen Hao stroked his chin: "So, as long as I don't move around, it won't treat me as an intruder?"

"That's how it is in theory."

"While it hesitates, could I let you connect and see what's inside?"

“We can try.” Nana glanced at the crater in the center. “But once the alarm is triggered, all exits will be immediately sealed off, and we’ll be locked here.”

"Didn't we already lock it once before?"

"That was a test mode. This time, if we go into mandatory quarantine, an alloy barrier will rise up outside the door."

Chen Hao grinned: "Wow, this place is even more strictly managed than an internet cafe."

Nana didn't reply, but slowly approached the main control platform. Her steps were very light, each step landing precisely on the seams between the floor tiles, as if afraid of disturbing something. The other three stood still, their eyes fixed on her every move.

She crouched down and lifted a stone slab. Below was a square socket, different in shape from the previous one, with three ring-shaped engravings along the edge.

“The new interface,” she said, “supports bidirectional data flow.”

"Can it be used?"

“If you’re going to use it, you have to take risks.” She glanced back at Chen Hao. “If the system determines that the access is unauthorized, it will start a self-destruct countdown.”

"how long?"

"Seventeen minutes."

"Is it enough for us to escape?"

"not enough."

The air was still for a few seconds.

"So what are you planning to do?" Chen Hao asked.

“Disrupt its scanning rhythm first.” Nana looked up at the red light. “It’s scanning every three seconds now, at a stable frequency. I want it to think this is a normal system self-check process.”

How to interfere?

“Use a flashlight.” She pointed to the equipment on Chen Hao’s waist. “Still a 3.7 Hz flashing frequency. Sweep it from left to right, keeping the rhythm steady.”

Chen Hao took out a light, turned it on, and then turned it back on. A blue light flashed, and the red light indeed lagged behind by half a beat.

He tried again, flashing four times in a row. This time, the red light paused for a longer period.

“It works,” Nana said. “Let’s do it two more times, and once it gets used to the rhythm, I’ll connect it.”

Chen Hao did as instructed. The flashlight beam traced a short arc on the wall. The red light shifted slightly, as if its train of thought had been interrupted.

In that instant, Nana reached out and inserted her connector into the groove.

The screen lights up.

External Equipment Testing

[Request Permission Verification]

Nana immediately pulled up the protocol templates in the database, selected the closest one, and sent it disguised as a "historical log back request".

A few seconds later, the interface redirected.

A line of text appeared: [Welcome to the Planetary Control System Main Terminal]

"They're inside?" Susan held her breath.

“It’s just the front desk.” Nana quickly scanned the page. “The core data is still behind the encryption layer.”

She began searching through the logs. The system was slow, taking five or six seconds to load each time. But she discovered a pattern—whenever she used a low-frequency signal to simulate the system's heartbeat, the response speed increased.

“It’s old,” she said. “It’s less than 40 percent as efficient as it used to be.”

"How long can it last?"

“I don’t know. But the temperature is rising.” She touched the area around the interface. “The metal is already getting hot.”

Chen Hao leaned closer: "Did you find anything?"

“Found it.” Nana opened a document. “A hundred years ago, a research team was conducting deep energy extraction experiments here. They wanted to extract stable energy from the Earth’s core, but an operational error triggered a chain reaction that almost caused the entire planet to disintegrate.”

"Then what?"

"The system shut down automatically, and everyone evacuated. But since then, this early warning mechanism has been running intermittently."

"So those vibration records we see..."

“It’s the alarm bells that are ringing,” Nana nodded. “Volcanic eruptions, tsunamis, storms—every disaster is preceded by underground energy fluctuations. It remembers the time and the intensity.”

Susan frowned: "But we haven't been digging into the Earth's core lately, so how come something happened again?"

“It’s not what we’re digging now.” Nana pulled up a star map. “It’s from three months ago, during our exploration of the deep-sea ruins. Do you remember? We opened an abandoned node.”

"You mean... we accidentally restarted a subsystem?"

“More than one.” Nana zoomed in on the image. “Six relay stations have been activated, and energy has begun to flow again. The previously dormant regulating array has been disturbed and is now in an unstable state.”

"So these natural disasters..."

“We caused this,” Carl said in a low voice.

Silence fell over the hall.

After a few seconds, Chen Hao scratched his head: "We didn't create this problem, but we have to clean it up."

He pointed to a red dot in the center of the star map: "There is a main control program in here. As long as someone goes in and resets it, the system can be restored to normal."

Can it be operated remotely?

“No.” Nana shook her head. “The automation module has long since failed. Someone has to go to the core location and manually input the restart command.”

How far is it?

"The straight-line distance is approximately eight kilometers, and the vertical depth is four thousand meters."

"Going down is easy, but coming back up is hard, right?"

“We might not be able to get up,” Nana said. “The passageway is old and in disrepair and could collapse at any time. Moreover, the closer we get to the core, the greater the radiation and pressure; ordinary protective suits won’t last more than ten minutes.”

Carl looked at the ground: "Then we can only choose one person to go."

"Who's going?" Susan asked.

No one answered.

Chen Hao sat down on the steps, took out his notebook, tore off a page, and began to draw a route sketch. As he wrote, he muttered to himself, "Go back to base first, and bring all the usable equipment. Oxygen cylinders, reinforced ropes, pressure suits... and I also need to find a communication device that can withstand high pressure."

Nana packaged all the data and stored it in local storage: "I will compile an action plan, including the best path, risk points, and backup plans."

"What do you think the success rate is?" Susan asked.

“I don’t know,” Nana said, “but if we don’t do it, a complete geological collapse will occur within three months. At that time, not only the base, but the entire area will collapse.”

“That means there’s no other choice,” Carl sighed.

Chen Hao closed the notebook and stuffed it into his pocket: "Anyway, I'm just killing time."

As he said this, the triangular light pattern above his head suddenly stopped.

The lights went out one by one.

In the end, only the central pillar remained, still glowing with a faint blue light.

The ground trembled slightly.

Nana unplugged the connector and closed the stone slab: "The system has entered hibernation."

"Does it know we're leaving?" Susan asked.

“It’s not that I knew,” Nana stood up, “it’s that I foresaw it.”

The four people stood in the center of the hall, and none of them moved.

Chen Hao glanced at his watch: "It's still a twenty-minute drive back. Let's get out of here before they change their minds."

They turned and walked back the way they came.

When she reached the entrance of the passage, Nana stopped and looked back.

The glowing pillar suddenly flashed.

It's like a response.