17. Sour

The sun was still scorching, the desert still dead silent, and the lurking dangers hadn't diminished in the slightest, but something was indeed quietly changing. The burden on Su Lin's shoulders seemed to have lightened, yet also grown heavier—the lighter burden was no longer having to constantly worry about the absolute safety of this fragile companion, the heavier burden of having to guide a young man, who had just mastered dangerous power and whose mind was still immature, on the right path.

Xingchen's body remained frail, the long journey and malnutrition leaving him resembling a slender reed. Yet, those eyes, once filled with fear and anxiety, now held an indescribable calmness and a cautious, growing tenacity. He continued to rush to do everything within his power: gather firewood, find water, and clean up camp. His movements were more nimble than ever, his gaze more focused. He was no longer merely passively accepting protection; he began to actively observe and learn, striving to truly become the "companion" Su Lin had described as "protecting each other."

Su Lin saw his efforts and was pleased, but also more cautious. He no longer left Stardust behind him. Instead, when he encountered sporadic zombies that did not pose much of a threat, he would deliberately let Stardust try to use his abilities.

The first practice took place the afternoon after leaving the riverbed. A lone zombie, its intestines half dragging out, staggered out from behind a pile of rubble, blocking their path. Its gray eyes rolled around blankly before finally locking onto the scent of a living person and letting out a low, hoarse growl.

Su Lin stopped and didn't rush forward to clean it up as usual. He turned his head to look at Xingchen, who tensed up and breathed rapidly. He reminded him in a steady voice, "Relax, Xingchen. Remember, you're in control of it, not it. Try it like last time, but not so violently. Just... let it go."

Xingchen swallowed hard, his face pale, his fingers curled nervously. The strange, terrifying memory instantly flooded back, making him instinctively feel fear and repulsion. But when he saw Su Lin's calm, encouraging gaze and recalled the oath he had made, he took a deep breath and forced himself to calm down. He closed his eyes and tried to concentrate, sensing the source of the chaotic, cold signal.

The process wasn't smooth. His mental tentacles, like clumsy probes, clumsily attempted to connect with the chaotic vibrations representing the zombies. The first attempt only caused the zombie to pause, whimper in confusion, then charge forward with even greater fury. The second time, the zombie stopped and spun in circles, as if losing its target. Fine beads of sweat beaded Stardust's forehead, his temples throbbed, and waves of dizziness from the depletion of his mental energy washed over him.

"Very good, that's it." Su Lin's voice sounded at the right time, like a stabilizing force. "Hold steady. Give it a clear instruction, 'leave' or 'turn'."

Xingchen gritted his teeth and cleared all distracting thoughts, leaving only one clear thought in his mind: "Leave! Go right!"

Buzz... A weak but precise spiritual fluctuation spread out like a stone thrown into the water.

The zombie, which was originally spinning around violently, suddenly froze, its gray eyeballs moved, and then, as if it had really received an order that could not be disobeyed, it staggered stiffly and haltingly towards the depths of the ruins on the right, and soon disappeared behind the broken walls, even the hoarse sound gradually faded away.

Silence returned to the scene.

Xingchen breathed a sigh of relief, his entire body swaying as if he were collapsing, his face turning even paler. But his eyes instantly lit up with a mixture of disbelief, surprise, and accomplishment. He'd succeeded! He'd truly done it! Without causing panic or exhausting himself, he'd subdued a zombie!

"Brother Su Lin! I... I did it!" He looked at Su Lin excitedly, his voice trembling, but no longer with fear, but excitement.

Su Lin stepped forward, supported his shaky body, and nodded approvingly, his tone remaining calm. "Well done. Remember this feeling, and control the output of your strength. Precision is more important than brute force. This will allow you to hold on longer." He paused, then added, "Also remember this feeling of exhaustion, and understand your limits."

Xingchen nodded vigorously, taking Su Lin's every word to heart. This successful attempt was like a key, unlocking the tightly closed door in his heart that had been filled with fear of his own abilities. He began to understand that this power wasn't entirely a scourge; if harnessed carefully, it could become a tool to protect himself and those important to him.

For the rest of the journey, similar exercises were repeated while ensuring safety. Like a patient mentor, Su Lin guided Xingchen on how to more precisely manipulate his mental tentacles, how to achieve his goals with minimal effort—sometimes temporarily disorienting approaching zombies, sometimes sensing hidden danger a fraction of a second in advance and issuing a warning, and sometimes, like the first time, guiding a single zombie to change its path.

Xingchen's progress was visible to the naked eye. He gradually learned how to focus his attention during combat, using extremely subtle mental distractions to cause a momentary delay or deviation in the zombies charging towards Su Lin. This tiny distraction, in a life-or-death battle, could often create a decisive opportunity. As a result, Su Lin's combat became more effortless, and his injuries decreased significantly.

He would also proactively expand his perception while Su Lin was focused on other things. It was a strange feeling, like transforming his consciousness into countless invisible threads, spreading outward, touching those cold, chaotic "signal sources" and vaguely sensing the faint fluctuations of smaller life forms, such as mutant rats and insects. Once, he "heard" the sound of tumbling gravel in the distance, realizing it wasn't natural, but rather the work of several mutant hyenas lurking behind the rocks. He alerted Su Lin in time, allowing them to evade and avoid an unnecessary battle.

These contributions were small, insignificant, and even difficult to detect by outsiders. Aside from Su Lin, who was perceptive and secretly observing, who could have imagined that the frail-looking boy who always followed quietly behind possessed such strange and powerful abilities, and proved his worth through his silent actions time and time again.

Su Lin could clearly sense Xingchen's efforts and progress. The young man was carefully and persistently proving himself in his own way, striving to integrate into this "team" that currently consisted of only the two of them. His motivation was simply to stay by Su Lin's side and fulfill his oath of "protection."

This pure and persistent belief made Su Lin feel complicated. He admired Xingchen's tenacity and growth, but he was also vaguely worried about this overly concentrated emotional dependence and the potential and danger of the ability that had not yet fully revealed.

He would privately instruct Xingchen in even more detail, not only on power control but also on basic combat techniques and survival knowledge. "Strength is just a tool, Xingchen," Su Lin said softly during a break, watching the boy carefully clean the spare dagger Su Lin had given him. "True strength lies in the ability to wield a tool. No matter what abilities we possess, we must remember that we are human beings first."

Xingchen raised his head, not quite understanding, but still nodded seriously: "I remember, Brother Su Lin. As long as you don't despise me, I will always follow you and listen to you."

The relationship between the two, in this shared secret, constant teaching and complete dependence, has become more intimate and special. They are not just companions, but more like master and apprentice, allies who share a huge secret, and a unique family who warm each other in the end times.

Yet, Su Lin hadn't forgotten his true goal, nor the weight of his concern. He continued to leave marks at every appropriate point, ones only Lei Qing, A Yan, and Mu Lin could understand. Piles of stone, pressed white cloth, special bullets, ice crystal runes drawn on charcoal... Each mark carried his longing and conviction.

Sometimes, he would stare at the mark in a trance, while Xingchen would quietly stand by, watching Su Lin's profile soften, yet tinged with a touch of sadness. He knew in his heart that Su Lin was thinking of someone else. Those he had never met, but who seemed to occupy the most important place in Su Lin's heart. A trace of inexplicable bitterness would quietly pass through his heart, but he quickly suppressed it. Being able to accompany Su Lin like this was already a happiness he had never dared to hope for. He clenched his fists, telling himself to become more useful, to better protect Su Lin. Just so... maybe he could occupy a small, irreplaceable place in Su Lin's heart.

As they headed north, they crossed an increasingly desolate landscape. The weather grew colder, and the wind carried the chill of distant snow-capped mountains. The vegetation beneath their feet became increasingly sparse, with bare rock and sand becoming the dominant landscape. The journey became more difficult, and water and food resources required more careful planning.

Yet, in this boundless wasteland, seemingly forgotten by the world, two figures, one tall, one short, one steady, one immature, seem to form a complete, self-sufficient little world. One seeks a way home, leaving behind a mark of hope; the other learns and grows, silently proving her own worth and guarding the light before her.

Until one day, an unusual, vast, chaotic cloud of dust rose from the distant horizon. It wasn't a sandstorm, but rather... the sign of some large-scale biological movement. Su Lin stopped, narrowed his eyes, and a sense of foreboding rose in his heart. Beside him, Xingchen's face instantly turned pale. He covered his forehead with his hands, and his voice was filled with pain and panic:

"Brother Su Lin... there are so many... so many 'signals'... over there... it's very... chaotic... and... they're moving!"