The light filtering through the gaps in the iron plate momentarily blinded Chen Hao.

He raised his hand to shield his eyes, then casually took the flashlight from the steel beam and shone it on the spot where he had just plugged in the circuit module. A little white smoke was still coming from the connector, like an overheated socket.

“It moved.” Carl squatted down beside him. “It really moved.”

“It’s not completely broken.” Chen Hao stared at the edge of the iron plate. “It’s just a little loose. We need to give it another hit.”

The communicator beeped twice, and Nana's voice came through intermittently: "Pressure sensing circuit...there is still residual signal...it is recommended to disconnect the main control line."

“Speak plainly.” Carl patted the communicator. “We’re like fish in a can right now, we can’t understand the technical terms.”

“This hole isn’t completely closed yet.” Chen Hao pulled out the module and looked at it. “It recognizes this key, but the door only opens a crack. We need to find where the lock cylinder is.”

"Are you planning to dig?"

"What else can we do?" Chen Hao swept the bottom of the pit with his flashlight. "We can't just wait for food to fall down from above."

He moved to the spot where he had found the loose metal plate and used a multi-tool to pry it open. Underneath, half a broken cable was exposed, its connector rusted black.

“Look at this,” he said to Carl. “An older model connector, compatible with the module.”

Carl leaned closer for a look: "You mean, there used to be a control box here?"

"It's blown up." Chen Hao knocked on the wall next to him. "It was probably demolished a long time ago, and they're still using the remaining rubble to do their work."

Nana's voice rang out again: "Some early infrastructure files have been retrieved... The trap system uses a three-wire pressure-sensitive circuit... The main line should connect to the underground junction box."

"What do you mean?"

"Find the junction box." Chen Hao patted Karl on the shoulder. "We need to dig down."

Carl sighed, took the shovel, and started digging. The soil was wet and stuck to the shovel, impossible to shake off. The two took turns, and after ten minutes they were panting heavily.

“This isn’t digging a hole,” Carl wiped the mud off his face. “This is building your own grave.”

"Don't rush to write the epitaph." Chen Hao shone his flashlight on the corner of the pit. "Dig southeast, according to the blueprints."

"Where did the blueprints come from?"

"In my head." Chen Hao grinned. "Nana just slipped a fragment of a map into my bracelet, saying it's from the colonial era and is older than my mother."

How old is your mother?

Don't ask.

The two continued digging. When they were half a meter deep, their shovels hit something hard. Digging through the mud, they found a metal conduit with markings and numbers on its surface.

"Found it." Chen Hao placed the detector on it. "There are three wires inside, and the middle one is electrified."

Which one should we cut?

"Electrified."

"What if we're wrong?"

"Then let's all be buried alive." Chen Hao looked up at the metal plate. "We can't get out anyway."

He clamped the middle wire with insulated pliers and pulled hard. The wire snapped, and a muffled thud suddenly came from the bottom of the pit, like something deflating.

Nana immediately responded: "The pressure sensor has been deactivated... the structural stress is at zero... we can try to escape."

"Done!" Karl slammed his fist on the ground, splashing up a cloud of mud and water.

"Don't celebrate too soon." Chen Hao looked up at the iron plate. "The problem now is—how to lift this iron lid."

The two stood up and looked up at the top. The iron plate was about two meters wide and looked quite heavy. The walls were covered with barbs, making it impossible to climb up using any leverage.

"Push it with your hand?" Carl tried, jumped up and patted it, but it didn't budge.

“We’ll need tools.” Chen Hao touched the steel beam in his backpack. “One beam isn’t long enough, but we can piece them together.”

They took out the remaining half of the steel beam and secured it with straps to form a long pole. After several attempts, the length was still a little short.

"Let's try a different approach." Chen Hao suddenly squatted down. "Let's set up a scaffold."

"What will serve as the fulcrum?"

“A rock.” He pointed to a protruding rock at the bottom of the pit. “The lever principle, which we learned in elementary school textbooks.”

Carl rolled his eyes: "Did you really learn anything from elementary school?"

"I copied it during the exam." Chen Hao had already started setting up the steel beams. "Use an A-frame to hold the movable end of the iron plate, and we can pry it open by stepping on the other side and pressing down."

After ten minutes of hard work, the two finally got the scaffolding up. The steel beam rested on the edge of the iron plate, with the other end suspended in the air.

Who wants to go first?

"You're gentle, you try it first."

Carl stood at the end of the long arm and slowly lowered his weight. The steel beam bent and creaked. The iron plate overhead slowly lifted, creating a larger gap.

"It worked!" Carl shouted. "Again!"

Chen Hao then went up, and the two of them stepped on it together. The steel beam almost broke, but the iron plate was finally pushed open by nearly half a meter.

"That's enough!" Chen Hao let go of his foot. "I'll go up first."

He swung his backpack up and wedged it into the gap, then grabbed the edge and flipped it over forcefully. A rush of outside air filled his lungs, carrying a hint of post-rain earthy smell.

He lay on the ground catching his breath for a few seconds, then turned around and reached out his hand: "Get on."

Carl grabbed his hand and used it to climb out. The two collapsed to the ground, staring at the dark pit, neither of them saying a word.

"At least I'm alive." Karl spat. "Next time you say you want to collect materials, I'll just pretend to be dead."

"Didn't we find something this time?" Chen Hao sat up, turned around and dragged out the steel beams one by one, then jumped back into the pit, dug out the black circuit module and stuffed it into his bag.

“Keep this thing,” he said. “A trap that can be turned on means there is still energy left in this area.”

What do you want to do?

"I don't want to do anything." Chen Hao dusted himself off and stood up. "I just think that maybe I can use it as a remote control in the future."

Susan's voice came through the walkie-talkie: "Your location has been confirmed. The drone has spotted you. Someone is waiting for you on the east side path. They'll be there in fifteen minutes."

"Someone's there?" Karl frowned. "Who?"

“Me,” Susan said. “Don’t tell me you’ve gotten into trouble again.”

"No." Chen Hao turned off the walkie-talkie. "Let's go home."

The two men carried the steel beam back. The sky was still overcast, the wind was light, and the road was muddy and difficult to walk on. Halfway there, Karl suddenly stopped.

"etc."

"What's wrong now?"

"Is that box in your bag... making a sound?"

Chen Hao was taken aback, put down his backpack and opened it. The black circuit module was on the top layer, and there was indeed a faint blue light flashing at the interface.

"It can still flash even when the power is out?" Karl leaned closer to look.

“It’s not out of power,” Chen Hao said, picking up the module. “It’s receiving signals.”

Who posted this?

“I don’t know.” He flipped it over to check the back, “but it’s definitely not the frequency of our base.”

The two exchanged a glance.

"Take it with you first." Chen Hao resealed the backpack. "Let Nana see it when we get back."

They quickened their pace. The lights of the base were already visible in the distance, a yellowish glow that stood out starkly against the gray sky.

Susan waited at the intersection with two other people, and only breathed a sigh of relief when they saw them appear.

"What about the materials?" she asked.

Chen Hao put down the steel beam: "One whole beam and one half beam, that's enough to get started."

Susan nodded, signaling her subordinate to take over the registration. Carl, on the other hand, headed straight for the living area, saying as he walked, "I'm going to take a hot bath. Anyone who tries to stop me will have to deal with me."

Chen Hao stood still, glancing down at his bracelet. The signal was normal, the map interface was open, but a red dot in the corner kept flashing, its location pointing in the direction they had returned from.

He didn't say anything, he just tightened his backpack.

Nana's voice came over the base's loudspeaker: "Materials have been stored. Thermal imaging confirms all personnel are in good health. Chen Hao, please come to the command post to sign the receipt."

"Coming," he replied, turning and walking inside.

As he passed the warehouse, he saw the steel beam placed in the maintenance area, next to several old cables. The technical team had already begun disassembling and measuring it.

He paused for two seconds, then turned and continued walking forward.

At the command console, Nana was bringing up the data panel.

"Submit the module," she said.

Chen Hao took the black box out of his bag and placed it on the table. The blue light was still flashing.

When Nana connected to the interface, the screen flickered and displayed a line of text:

[Authentication Request: Enter Permission Code]