Apocalypse: I Built the Infinite Train

Chen Sixuan gasped, covering her mouth in shock. "There are actually people down there!"

"Let’s hear them out first," Lin Xian gesture for silence before pressing the responder again. "We can hear you."

"This is Ding Junyi, Deputy Director of the Biological Research Department in Underground City No. 9. The city has been overrun by a massive outbreak of zombies and nocturnal entities. My colleagues and I are currently trapped on Level -52 in the research sector. Can you assist us? If you're willing to help, we can offer a trade."

Her voice carried a hint of urgency, but on the Infinite Train, the crew’s expressions darkened.

"Are you saying… out of this entire underground city, only a few of you survived?"

Lin Xian’s first instinct was to doubt her claim. He had encountered too many baited traps before—this wasn’t something he would easily fall for.

"The exact number of survivors in other areas is unknown," Ding Junyi replied. "Two weeks ago, the excavation teams in the lower levels encountered an unidentified subterranean lifeform, which led to an emergency shutdown of operations. Core Reactor No. 1 suffered a meltdown, triggering widespread mutations and infections. As a result, at least 376,000 citizens—over 95% of the population—perished. The Underground City Federal Management Committee was forced to initiate an evacuation, deploying 8 intercontinental-class trains, 3 Eternal-class trains, and numerous airships, helicopters, and flight units to transport key personnel. However, nearly all airborne evacuation vehicles went missing over the Daluo Mountains. Preliminary analysis suggests they were intercepted by airborne nocturnal entities."

"The mutations triggered large-scale chaos, severely damaging the city’s infrastructure. Zombies swarmed the underground levels, and nocturnal entities appeared in large numbers. My three colleagues and I failed to escape in time and were forced to take refuge in a biological research lab. As of now, there are likely very few survivors left in Underground City No. 9. We were able to locate you via surveillance feeds at GF2 Station, which is why we’re reaching out for help."

Despite requesting aid, her voice remained unnervingly calm.

"Huh. So not only are there people here… but there’s still power."

Lin Xian nodded, scanning his team’s faces. He was certain that the nocturnal entities Ding Junyi mentioned were the same as the Eerie Entities they had encountered before. Pressing the responder again, he asked,

"How exactly do you expect us to rescue you?"

They had no idea what lay ahead. From what Ding Junyi described, an unknown creature had emerged from the underground, zombies and nocturnal entities had taken over, and they were stuck 52 levels below. Even if Lin Xian wanted to help, he needed more information first—this could just as easily be a death trap.

Ding Junyi wasted no time responding.

"Currently, elevators 1, 2, and 5 are completely destroyed. Elevators 7 and 8 only reach Level -80 and below, which are already overrun with infected. The only functioning elevator is No. 3, which is a freight elevator for transporting equipment. It leads to the underground Level-95 Freight Rail Terminal, but due to structural damage, it can only reach Level -89 at best.

"I can remotely unlock the security gate leading to GF2 Station’s underground track, but we only have a backup power source. There isn’t enough energy to power the rail elevator for your train. However, your train can still take the direct tunnel down to Level -65 Freight Terminal. From there, you can use Elevator No. 3 to reach us on Level -52. There are plenty of zombies outside, but given your heavy firepower and the presence of a psychic ability user, the risk should be manageable."

Lin Xian frowned slightly.

From her explanation, her identity as a Deputy Director of Biological Research seemed highly credible. A regular underground city citizen—even high-ranking officials—wouldn’t have such detailed knowledge of the city’s infrastructure. Her logic was clear, her planning methodical, and she spoke in the precise tone of a researcher.

Still, Lin Xian wasn’t fully convinced.

"You make it sound easy. Why didn’t you contact the federal government for help?"

KIKI leaned in, her sharp intuition kicking in. "Yeah, why didn’t you call for an official rescue?"

Another voice—this one younger and more anxious—cut in through the responder.

"Because the underground city’s satellite communication systems were taken during the evacuation! Standard communication devices are useless due to the Dark Night Magnetic Waves, which you should be well aware of! The only systems we have access to now are the city’s subsystems, which is why we’re using the station’s responder to contact you!"

Lin Xian’s brows furrowed. "So when the evacuation happened… no one came to get you?"

A brief silence followed. Then, Ding Junyi took over the call again.

"Our distress calls were received," she said plainly. "But given the circumstances… we were likely classified as abandoned assets."

Inside Underground City No. 9, deep within a sealed-off research sector, the quarantine doors remained locked.

The outer hallways were pitch black, infested with wandering zombies. Inside the lab, four researchers—two men and two women—huddled together, their faces filled with anxiety. They had been trapped here for over a week.

Despite the high-level security measures and life support systems, food and supplies were critically low. If they didn’t escape soon, they would starve to death.

Ding Junyi, the Deputy Director, was in her early thirties, her sharp gaze framed by glasses. With her were Zhao Yan, Xu Wen, and Han Qiming, a microbiologist.

The oldest among them, Zhao Yan, was visibly weakened. They had resorted to eating experimental green plants to sustain themselves. Fortunately, the lab still had functioning lighting and air circulation, preventing them from suffocating.

Since the Great Evacuation, the underground city had turned into a nightmarish wasteland. Roads were blocked, the Polar Night had descended, and their chances of rescue were growing dimmer by the day.

Nearly all useful resources had been taken during the evacuation. This half-finished, post-apocalyptic megastructure—barely 175% completed—had become nothing more than a graveyard of despair.

"Director Ding… I don’t think they trust us."

Xu Wen, the youngest and most timid, was growing frantic. The silence on the responder made her panic. "What do we do?"

"Stay calm," Han Qiming replied, scratching his messy, unkempt hair. He was already skeletal after two weeks of starvation. "They came in on a train, which means they have a purpose here. Plus, they opened the security gate and have high-tier abilities. They might want to explore the underground city anyway. If that’s the case… we can find common ground."

"Exactly."

Zhao Yan, the eldest, turned to Ding Junyi. "Director Ding, should we just ask them directly?"

Ding Junyi, however, remained calm as ever.

Instead of replying, she silently reviewed the security footage, rewatching how Lin Xian’s group had breached GF2 Station. Unlike the others, she wasn’t focused on whether the train crew would help them—she was studying them.

Taking notes on her tablet, she analyzed the video carefully.

"They have five people visible in the footage so far," she noted. "It’s unclear if there are more onboard. The leader is the man speaking with us. Estimated age: 25-30. Clear sense of purpose, logical thinking, highly educated. He opened the GF2 Station gate—I checked the system logs. No authorization was granted, which means he likely has an advanced mechanical ability and forced it open."