Chen Hao's fingers trembled slightly as he pressed them against the control panel. Not out of fear, but excitement. He had just plugged in the laser equipment when the green indicator light came on, and the screen displayed: System self-test complete.

"Is it working now?" he asked Nana, turning around.

Nana stood beside the equipment, her finger rapidly swiping across the projected interface. "Fuel pressure has stabilized, output power adjusted to 60%. Cutting can begin."

"Then what are we waiting for?" Chen Hao grinned and tightened the safety fence again. "Karl, keep an eye on the vents and make sure they don't smoke. Susan, keep track of the time. This thing is very precious right now, we can't go over the time limit."

Carl crouched behind the machine, holding a thermometer in his hand. "Understood, stop it as soon as it gets hot."

Susan pulled out a worn-out whiteboard and wrote "First assignment: Ready" in charcoal.

Nana walked to the control panel, her finger hovering over the start button. "Target area locked, focus complete. Ignition in three seconds."

No one spoke.

The air felt like a taut rope.

"Three, two, one."

She pressed the button.

A beam of blue-white light shot out from the front of the device and struck the surface of the rock. There was no explosion, no roar, only a sharp "sizzle," like a piece of metal scraping against glass. The rock where the beam touched the surface quickly turned red, and then fine fragments flew out, piling up into a ring of grayish-white powder on the ground.

"Holy crap!" Chen Hao exclaimed, his eyes wide. "It actually cut in!"

The cut wasn't wide, but it was deep, piercing straight into the stone like a knife plunged into frozen flesh. Ten seconds later, Nana turned off the laser; the beam disappeared, leaving a neat crack, at least twenty centimeters deep.

"It worked?" Susan leaned closer to look. "Just like that?"

“A successful entry.” Nana withdrew her hand. “The rock structure has undergone localized vaporization, significantly reducing resistance. The next round can proceed along this path to deepen the depth.”

Chen Hao slapped the machine's casing. "Wow, high technology is really something else. Places that we used to struggle to gnaw on with 'Groundhog No. 1' can now be done in ten seconds."

Carl stood up and wiped the sweat from his brow. "The question is, how many times can it do it?"

Nana brought up the data panel. "Current fuel remaining supports seven complete operating cycles, each lasting fifteen minutes, with an eight-minute cooling interval. Continuous use will cause the equipment core to overheat."

"Seven cuts should be enough for one section." Chen Hao rubbed his hands together. "Hurry up and clean up the slag, then continue with the next cut."

The three of them got to work, using shovels to move the chopped-off stone chips aside. The rock's cross-section was so smooth it didn't look naturally formed; the edges were slightly blackened, as if it had been burned. Susan rubbed it with her finger, and her fingertip immediately picked up a layer of fine ash.

“This thing cuts even more precisely than a saw,” she said.

“Because it’s not a saw,” Nana said, standing nearby. “It’s burned through.”

The second round of cutting began quickly. This time, the goal was to penetrate the deep rock mass beyond the first cut. Nana recalibrated the angle to prevent beam deviation from damaging the equipment's front-end lens.

The laser turned on again.

This time, the cutting speed was even faster. There seemed to be tiny cracks inside the rock, and the high temperature caused these cracks to expand rapidly, making the entire rock loosen. Thirty seconds later, a large piece of rock broke off with a "crack," hitting the ground and shaking it.

"It's open!" Chen Hao jumped up. "The tunnel entrance is open!"

Behind the gap was a hollow cavity, with a dark opening extending forward like an open mouth. The wind blowing in carried a musty, earthy smell.

“It’s not too deep,” Carl peered inside, “but deep enough for a person to get in.”

"Then let's go in." Chen Hao grabbed a flashlight and was about to crawl inside.

"Wait a minute." Nana stopped him. "The air quality hasn't been tested. There might be a risk of gas buildup or landslides."

"Then take a look." Chen Hao handed over the light. "Hurry up, I've been wanting to see what's inside all the way here."

Nana took out her portable detector and inserted it into the hole. A few seconds later, data appeared on the screen: "Oxygen content normal, no harmful gases. Structural stability rating: moderate. We recommend reinforcing the structure before proceeding further."

"Medium is fine." Chen Hao breathed a sigh of relief. "It's better than being stuck at the door."

Instead of rushing forward, they first cleared away all the debris and moved the laser equipment near the tunnel entrance for easier follow-up attacks. Susan drew a mark on the wall with chalk: "First breakthrough point."

"What do we do next?" she asked.

"Cut it in sections." Chen Hao sat down, panting. "Cut one section at a time, clear it completely before moving forward. Don't rush, save fuel."

Carl nodded. "I did the math, and at this rate, we can get the first five meters through. After that, we'll have to figure out how to refuel."

"Replenish?" Susan frowned. "Where do you think we can find these special containers?"

“It doesn’t necessarily have to be the original.” Karl stroked his chin. “The compressed fuel used in old generators has a similar composition. If it can be purified, it might be usable.”

“Let’s give it a try,” Chen Hao said. “But let’s get to work first. We went through so much trouble to split the stone; we can’t just leave it here.”

The third round of cutting begins.

The goal this time was to widen the passage laterally so that two people could pass side by side. Nana set up an automatic scanning path, and the laser moved slowly along the predetermined lines, shearing away the rock layer by layer like a tailor cutting fabric.

Chen Hao stood to the side, watching intently. "If this thing had come out a few years earlier, why would we even need to dig subways? We could just use lasers to clear the way, and build ten lines a day."

“The energy consumption is too high,” Nana said. “It won’t be used in civilian projects.”

“This is a life-saving project, so we’re not concerned with economics,” Chen Hao chuckled. “Anyway, it’s under my management now, so I’m in charge.”

By the time the fourth round of work was finished, it was already dark. The tunnel had advanced nearly three meters and was wide enough. They set up temporary lighting at the entrance and built a makeshift support structure using planks and steel pipes to prevent falling debris from above.

"Let's take a break." Chen Hao plopped down on the box. "I'm hungry."

Susan took two compressed biscuits out of her bag and handed him one. "Eat this, but be careful with your chewing, we don't have much left."

"Once we get through, we'll have a new base." Chen Hao took a bite, the dry food making his mouth water. "Then we can rummage through the warehouse, find food, and get new equipment. We can still make a living."

After checking the equipment, Carl walked over and sat down. "Fuel left for five charges."

The room fell silent for a moment.

"Is five times enough?" Susan asked.

"It depends on how you use it." Nana opened the log. "If it's only used for clearing obstacles at key points, it can cover the more difficult sections of the remaining seventy meters. But it can't be relied on for the entire journey."

“That means it can’t be used as the main tool.” Chen Hao brushed away the biscuit crumbs. “We need to be more careful with our resources.”

“We can also recycle waste,” Carl said. “There are a few high-pressure gas tanks in the pile of old cars over there, which may contain some residual inert gas that can help stabilize the pressure.”

"You're going to dismantle it?" Susan raised an eyebrow.

“I’ll go tomorrow,” Carl said, “and see if there are any other usable parts.”

Chen Hao looked up into the depths of the tunnel, the beam of his flashlight stretching endlessly. "We're moving forward now, but we haven't completely solved the problem."

“At least we don’t have to dig with our hands anymore.” Susan smiled.

"That's true." Chen Hao stood up and stretched his arms and legs. "Come on, one last cut. Let's deal with that hard part at the corner first, so we can continue tomorrow."

The fifth round of cutting begins.

The laser beam sliced ​​across the rock face, sparks flying. The rock cracked softly, like ice slowly splitting open in the sunlight. The cut deepened until finally, the last piece of rock in the way loosened and collapsed into the hole with a crash.

"It's connected!" Chen Hao shouted.

The tunnels were finally connected in a straight line, eliminating the need for detours.

He stood at the entrance, gazing at the dark passage ahead, and smiled.

“Let’s go,” he said. “Let’s continue.”

Nana turned off the equipment and began recording energy consumption data. Susan squatted down next to the fuel tank, turned on the detection valve, glanced at the reading, and frowned slightly.

Carl took the instruments from her hand and said in a low voice, "The descent is too fast."

"Twenty percent faster than expected," Susan said. "Is something leaking?"

“Not necessarily,” Carl shook his head. “It’s possible that vibrations during transport caused minor damage to the seals, leading to fuel evaporation.”

No one spoke inside.

Chen Hao was still gesturing at the tunnel entrance, planning the next route, muttering to himself, "Add a support here, leave a ventilation opening there..."

Nana looked up at the fuel monitor.

The red warning light flashed once.