While Lin Kezhi was speaking, Xia Ye gazed out the window. Beyond it stretched a vast expanse of golden wheat fields, steadily receding as the train sped onward.

“So, let’s chat,” Lin Kezhi said. Ever the social butterfly, he nudged Xia Ye with his elbow. “What’s your ideal type? I’ll help you find one.”

Xia Ye turned to him.

“I’ve never thought about it.”

“You’ve never thought about it? No way.” Lin Kezhi looked utterly disappointed. “Xia Ye, let me tell you—you’ve become a celebrity on this train. After what just happened, everyone knows who you are. On my way here, I don’t even know how many sentinels were asking about you.”

Naturally outgoing, he was never short on words.

“Don’t worry. I know about half the people on this train. If you’ve got your eye on someone, just tell me. I’ll help you vet them.”

Xia Ye shifted his gaze to Lin Kezhi’s face. The coldness from earlier had faded, replaced by a touch of warmth.

“Thank you, but I really don’t need to.”

Faced with such a clear rejection, Lin Kezhi deflated like a punctured balloon.

“Then what are you going to do for the entrance assessment? You’ll need a partner, won’t you?”

Xia Ye suddenly smiled. His eyes flicked toward the seat beside him, the implication unmistakable.

“I’ll be fine on my own.”

Following his gaze, Lin Kezhi glanced over before breaking into laughter, clearly enjoying someone else’s misfortune.

“True enough. The two of them together couldn’t even beat you. Why bother finding a sentinel just to drag you down?”

His cheerful tone lightened the atmosphere, drawing a faint smile from Xia Zhi as well.

The tense mood that had filled the carriage earlier quickly dissipated.

“So, Xia Ye,” Lin Kezhi said with a grin, “does that make me your first friend at school? You’ll have to look out for me from now on.”

Xia Ye nodded.

He didn’t mind calling Lin Kezhi a friend. If anything, the thought brought him a measure of comfort.

Lin Kezhi was right; He really was his first friend at school.

And the first friend of his life.

Selfishly, Xia Ye would rather acknowledge Lin Kezhi as his first friend than call that other person one.

He wanted that person to occupy a place that was even more special.

—

In truth, Xia Ye had only met that person once.

He was a sentinel with an air of perpetual indifference, always wearing a cigarette tucked behind one ear, looking as though nothing in the world could concern him.

When Xia Ye first saw him, he was gravely injured.

A horrifying wound slashed across his back, so deep it had nearly torn him apart. Bright red blood seeped through the bandages, vivid and shocking to behold.

Xia Ye had seen a wound like that before.

During the extraterrestrial contamination that had nearly destroyed his entire life, a mantis-like extraterrestrial creature had ripped open his mother’s back in exactly the same way.

She hadn’t survived even fifteen minutes after being wounded.

The injury had been too severe, and no medicine could stop the endless flow of blood.

By the time the bed sheets had been soaked crimson, his mother had stopped breathing.

Seeing such a wound again made Xia Ye’s heart skip a beat.

But the man merely glanced at him nonchalantly.

“Scared?”

Xia Ye shook his head. He wasn’t afraid. Nor was he willing to admit that he was.

Driven by an impulse he couldn’t explain, he stared fixedly at the man before him.

“You’ve got guts for a kid,” Chi Zhou said absentmindedly with a faint smile. “Is there a medical station around here?”

Xia Ye shook his head again.

The medical station in District Twelve had been shut down three years ago.

Now, only underground clinics remained.

“I’m not a kid,” he said. “I’m fourteen.”

Only then did Chi Zhou give him a proper look.

At fourteen, Xia Ye had already begun to shoot up. Standing amid the refuse scattered across the contaminated district, he resembled a young poplar tree bursting with spring vitality.

He was simply too thin.

His shoulders looked as fragile as paper. It was obvious that this was a child who had grown up in the contaminated zone. Years of extraterrestrial contamination had inflicted irreversible damage on the health of District Twelve’s residents.

Fortunately, Xia Ye was still young.

The black market carried certain rare treatments capable of repairing genes damaged by extraterrestrial contamination.

Chi Zhou looked him up and down before flashing a roguish grin.

“How about a deal? Find me a place to stay, and I’ll take you somewhere interesting.”

Xia Ye immediately judged it to be a losing bargain.

District Twelve wasn’t that big. He had lived there for over a decade, so there couldn’t possibly be anywhere he hadn’t already been.

Even so…

He agreed.

“At least tell me your name.”

Staring at the ground, Xia Ye unconsciously nudged a pebble with the tip of his shoe.

“Chi Zhou.” He scratched his hair, looking oddly embarrassed. “You’ve probably heard of me.”

Xia Ye’s eyes widened.

Of course he had heard that name.

There was probably no one in the entire Human Alliance who hadn’t.

“So…you’re a sentinel?” Without realizing it, a hint of anticipation crept into Xia Ye’s voice.

Chi Zhou nodded. “Yeah.”

It was an obvious fact.

He couldn’t understand why Xia Ye felt the need to ask. Perhaps children from District Twelve were simply more cautious about such things.

Xia Ye’s steps immediately grew lighter.

He had never imagined he would actually meet the Chi Zhou.

The first Dark Sentinel in human history.

A century earlier, during the extraterrestrial contamination crisis, it had been Chi Zhou who single-handedly held back the extraterrestrial invasion, buying the Human Alliance precious time to recover.

His name existed in history textbooks.

It appeared in the Alliance’s annual New Year’s Gala.

It lived on in countless legends.

But it had never existed in Xia Ye’s life.

District Twelve lay on the outermost fringes of the Alliance.

It was a place where vermin thrived and darkness flourished.

He had no idea why Chi Zhou had come here.

—

Xia Ye brought Chi Zhou back to his home.

It was an old, dilapidated apartment. One of the windowpanes had shattered long ago, and Xia Ye had patched the hole with old newspapers to keep out the howling winter wind.

“It’s a little shabby,” Xia Ye said bluntly as he opened the door. “But no one will find you here.”

Chi Zhou pulled out one of the dining chairs and gestured for Xia Ye to sit before taking the chair opposite him. “No one lives here?”

“How did you know?” Xia Ye asked.

Whenever Xia Ye managed to sneak out of the orphanage, he would come here. He always kept the apartment spotless because couldn’t bear to let his memories gather dust.

“It doesn’t smell lived in,” Chi Zhou said with a shrug. “You don’t live here?”

Somehow, he produced a roll of bandages and set it on the wooden dining table.

Then he turned sideways and peeled away the blood-soaked bandages wrapped around his back. The movement was practiced, as though he had done it countless times before.

The gruesome wound came into view. Part of his ribs was faintly visible through the gash. Against the backdrop of his well-defined muscles, it looked even more terrifying.

After hesitating briefly, Xia Ye walked over and picked up the bandages. He was extraordinarily careful.

Chi Zhou barely felt any tug on the wound before the bandaging was finished.

“You’re pretty good at this,” Chi Zhou remarked.

Keeping his head lowered, Xia Ye remained silent for a moment.

He didn’t know much about medicine.

But during the contamination disaster, he had dressed wounds like this more times than he could count.

Standing behind Chi Zhou, he finally answered the earlier question.

“They said it’s not safe for minors to live alone.”

Understanding dawned on Chi Zhou.

Xia Ye owned an apartment but wasn’t allowed to live in it.

The conclusion was obvious.

Something had happened to his parents.

According to regulations, he could only stay at the orphanage operated by the Public Safety Bureau.

Xia Ye must have thought long and hard before deciding to tell him the truth.

Chi Zhou didn’t press the subject.

Instead, he stood up. “I’ll walk you back.”

—

Half a month later, Xia Ye keenly noticed that life at the orphanage had become noticeably better. Breakfast portions were no longer skimpy, and the bedding was thicker and warmer.

Whenever the other children mocked Xia Zhi, a teacher would mysteriously appear out of nowhere, drag the troublemakers away, and give them a thorough scolding.

With no more need to fight the children who bullied his sister, Xia Ye gladly devoted all of his time to studying sentinels, guides, and the Alliance Military Academy.

Through Chi Zhou’s stories, he discovered another world—a world that didn’t exist in District Twelve. Perhaps he had once had a chance to enter it, but the extraterrestrial contamination that had taken everything from him had erased that possibility.

Then Chi Zhou gave that opportunity back to him.

Chi Zhou had long since left; he had stayed in the apartment for only three days.

But he had kept his promise to take Xia Ye somewhere special.

The black market.

Xia Ye had always believed there was nowhere in District Twelve he didn’t know.

Yet as Chi Zhou led him through twisting alleys, across abandoned ruins and underground basements, Xia Ye realized once again just how small his world had been.

Chi Zhou told him many things.

About sentinels and guides.

About awakening and psychic power.

About the Alliance Military Academy.

About extraterrestrial contamination.

Finally, Chi Zhou brought him to the far end of the black market, where someone dressed in a white lab coat was waiting.

Chi Zhou nudged Xia Ye forward.

“Two Grade-A Purification Agents. Use them immediately. After that, one dose every week. Deliver them to…”

He looked at Xia Ye.

Xia Ye gave the apartment’s address before explaining, “Where I live isn’t convenient.”

“Grade-A Purification Agents are currently out of stock. The optimal alternative is four Grade-C Purification Agents,” the figure in the white coat replied in a mechanical voice. “Your order has been received. It will be delivered to the specified address. Thank you for your patronage.”

A stack of invoices rustled out of the lab coat’s pocket.

Chi Zhou stuffed them into his own pocket, uncapped one of the Purification Agents, and pressed it into Xia Ye’s hand.

Xia Ye shook his head. “I can’t afford this.”

He had caught a glimpse of the invoice. The total was an astronomical figure beyond anything he could possibly pay.

“It’s your payment,” Chi Zhou said. “You saved my life. You deserve it.”

Xia Ye knew it was only an excuse. When he had found Chi Zhou, the man hadn’t seemed weak at all.

“Xia Ye.”

Chi Zhou suddenly called his name, his tone growing more serious. “The Purification Agents can repair the damage caused by extraterrestrial contamination. Take better care of yourself. Your body can’t take much more abuse.”

He could tell that Xia Ye had once suffered severe injuries during the contamination disaster. Although he had survived, his lungs had sustained irreversible damage. He coughed from time to time, and his body was far too thin. After a long silence, Xia Ye tilted his head back and drank the Purification Agent.

The medicine took effect almost immediately. Like a stream of clear spring water, it flowed through his battered bloodstream.

His head grew light. Yet more than dizziness, he felt relief. It was as though something murky had been washed out of his body.

“I’ll pay you back someday,” Xia Ye said stubbornly.

“Sure,” Chi Zhou replied casually. “I’ll be waiting.”

Xia Ye had always wondered whether those words had been a promise…

…or merely a joke.

After Chi Zhou left, Xia Ye came down with a high fever. The temperature frightened the orphanage teachers so badly that they even began discussing whether they should prepare a cemetery plot and flowers for him.

A week later, Xia Ye recovered without taking any medicine. The moment he opened his eyes, he realized the world had changed.

He could see the path of every wisp of wind.

He could hear the teachers whispering beside the fireplace.

He could feel the texture of the woven fabric beneath him.

This was the world of sentinels and guides.

It was also Chi Zhou’s world.

After awakening, Xia Ye became convinced that it had been a promise. No matter what Chi Zhou himself had intended, Xia Ye believed he was duty-bound to repay the kindness he had received.