SYSTEM NOTIFICATION: You are reading [Threshold Walker: The Silver Circuit]
"This is a terrible idea," Tae-Woo said, not for the first time.
They were crammed into a Network van disguised as a telecommunications service vehicle, parked a block away from the upscale care facility where Jin's mother had lived for the past three years. Professor Park's evacuation protocol had relocated them to a secondary Network safe house on the outskirts of Seoul—a converted warehouse with living quarters below and monitoring equipment above.
"I know," Jin acknowledged, scanning the street for Division patrols. "But after what happened at the university, I need to make sure Mom is safe."
"The Division wouldn't hurt her," Dr. Ha said from the driver's seat. "They need her cooperation to track you."
"It's not just about safety," Jin-Ah interjected. "Mom's condition has been getting worse. The Division 'treatments' aren't helping." She looked at her brother. "And after what you told me about the Clarity formula..."
Jin nodded. They'd spent the previous day at the safe house, Jin explaining everything he'd learned about threshold phenomena while Jin-Ah shared her own experiences with silver dreams and her independent research into their father's work.
"We'll be quick," Jin assured the others. "Just enough time to check on her and administer the modified Clarity dose."
Dr. Ha had worked through the night to formulate a gentler version of the Clarity treatment for Jin's mother, whose advanced threshold sickness had been managed with increasingly ineffective Division suppressants for years.
"The surveillance sweep is starting," Tae-Woo reported, checking his tablet. "You have a twelve-minute window before the next one."
Jin and Jin-Ah exchanged glances, determination mirrored in their expressions. Jin was still getting used to seeing his sister in this new context—not just as his academically accomplished younger sibling, but as a fellow threshold sensitive, albeit with much milder manifestations.
"Be careful," Dr. Ha said, handing Jin a small insulated case containing three vials of the modified Clarity. "This should help with her symptoms without the suppressive effects of the Division treatments. But there's no guarantee it will work on such an advanced case."
"It has to," Jin-Ah said simply.
They exited the van separately—Jin-Ah first, walking normally toward the facility entrance, and Jin two minutes later, hood pulled low over his face. Jin had practiced signature suppression extensively with Min Yuna before leaving the university, and now focused on dimming his threshold presence to near invisibility.
The Serene Meadows Care Center was a modern four-story building surrounded by carefully landscaped gardens. Its sterile elegance concealed its true nature as a specialized facility for patients with "neurological anomalies"—the Division's euphemism for threshold sickness cases they wanted to monitor.
Jin-Ah entered through the main doors, signing in as herself. As a registered family member who visited regularly, her presence wouldn't raise suspicions. Jin waited until she'd cleared reception, then slipped in through a side entrance using an employee keycard Dr. Ha had programmed based on security specifications from the Network's database.
The siblings had agreed to meet at their mother's room on the third floor. Jin navigated service corridors and stairwells, avoiding the main hallways where cameras would be monitoring. When he reached the third floor, he paused, extending his perception as Dr. Ha had taught him.
The silver lines formed complex patterns throughout the building, but Jin noticed something unusual—certain rooms showed brighter concentrations, pulsing with familiar rhythms. Other threshold sensitives, he realized. This wasn't just a care facility; it was a monitoring center for people with various stages of threshold sickness.
He made his way to Room 312, where his mother had lived since her condition deteriorated to the point where home care was no longer possible. Jin still remembered the day Division representatives had "suggested" she be moved here for "specialized treatment."
Jin knocked softly in the pattern he and Jin-Ah had used as children—two quick, one slow, two quick. The door opened immediately, Jin-Ah's relieved face greeting him.
"You made it," she whispered, pulling him inside and quickly closing the door. "I was worried when I saw the security guard making rounds."
Jin's attention immediately went to the figure in the bed by the window. Min-Seo looked smaller than he remembered, her once-vibrant face now gaunt, hair streaked with premature gray. She appeared to be sleeping, her breathing shallow but regular.
"How is she?" Jin asked, moving to his mother's bedside.
"The same," Jin-Ah replied, her voice tight with emotion. "Some days are better than others. Today... isn't great. She was talking about silver patterns in the walls earlier. The nurse gave her something to 'calm her down.'"
Jin reached out, gently taking his mother's hand. To his surprise, he could see faint silver lines tracing her veins, pulsing weakly—almost like they were being suppressed.
"The Division meds," he murmured. "They're not treating her; they're just keeping her threshold energy contained."
Jin-Ah joined him at the bedside. "Can your Network treatment help?"
Jin carefully removed a vial of the modified Clarity from the insulated case. "Dr. Ha thinks it might. Instead of suppressing the threshold energy, it helps the body integrate it." He hesitated. "But Mom's been on suppressants for years. There's no telling how she'll react."
A soft sound from the bed drew their attention. Min-Seo's eyes had opened, unfocused at first, then gradually sharpening as she became aware of her surroundings.
"Jin-Ah?" she murmured, then her gaze shifted. "Jin?" Confusion gave way to a brief moment of startling clarity. "You shouldn't be here. They're watching."
Jin squeezed her hand gently. "I know, Mom. But I had to see you."
Min-Seo's eyes darted to the corners of the room, then back to her children. "The silver lines. You see them now, don't you? Like your father."
Jin nodded, surprised by her lucidity. "Yes. And we think we can help you."
He explained the Clarity treatment as simply as possible while Jin-Ah prepared the injection according to Dr. Ha's instructions. Min-Seo listened with unexpected attentiveness.
"Your father tried something similar," she said when Jin finished. "Before... before he disappeared. He called it 'integration theory.' The Division doctors didn't approve."
Jin exchanged a startled look with Jin-Ah. Their mother rarely spoke coherently about their father or the events surrounding his disappearance.
"Mom," Jin said carefully, "do you remember anything about Dad's research? About the convergence circuit?"
Min-Seo's eyes suddenly focused with surprising intensity. "The seventeen points. Connected. A path home." Her hand tightened on Jin's with unexpected strength. "He said if he didn't come back, you would find the way."
Jin felt a chill run through him. "He knew? Even back then, he knew I would develop threshold sensitivity?"
"Not just sensitivity," Min-Seo said. Her gaze turned distant again, her voice taking on a dreamy quality. "The key. He put the key in your blood."
Jin-Ah, who had finished preparing the injection, froze. "That's exactly what The Collector said."
Min-Seo's attention snapped to Jin-Ah. "Kang Jae-Hwan? You've met him?" Fear flashed across her face. "Don't trust him. He wants the circuit for himself."
Before Jin could ask more, his mother's expression clouded with pain. She pressed a hand to her temple, wincing. "It's getting worse. The dreams. The voices from the between-place."
Jin made a decision. "Mom, we have medicine that might help. Not just suppress the symptoms, but actually treat them. Do you want to try it?"
Min-Seo looked at the vial in Jin-Ah's hand, then back to Jin. After a moment, she nodded. "Your father would have wanted me to trust you."
Jin-Ah administered the injection with practiced ease—her biomedical studies had given her experience with such procedures. For a few moments, nothing seemed to happen. Then Min-Seo gasped, her eyes widening.
"The silver," she whispered. "It's... flowing instead of burning."
Jin watched in amazement as the faint silver lines along his mother's skin brightened slightly, their rhythm changing from erratic pulses to a steadier flow. The constant tension in Min-Seo's face eased, and her breathing deepened.
"How do you feel?" Jin-Ah asked anxiously.
"Clearer," Min-Seo said with wonder. "Like... like waking up." She looked around the room, her gaze more focused than Jin had seen in years. "How long have I been here?"
"Three years," Jin replied gently.
Min-Seo nodded slowly, processing this information. "It feels like I've been underwater all this time. Everything was... muffled. Distant." She touched Jin's cheek. "You look so much like him now."
The moment of connection was interrupted by Jin-Ah's warning. "Someone's coming."
Jin extended his perception, sensing two people approaching—one with the characteristic void of threshold energy that marked Division personnel.
"Hide," Min-Seo urged, suddenly alert. "The bathroom. Quickly."
Jin hesitated, reluctant to leave his mother just as she was showing improvement.
"Go," she insisted. "I'll be fine. The medicine... I can think clearly for the first time in years." She squeezed his hand. "Your father's office. The answers are there. The fifth point."
Jin retreated to the bathroom with Jin-Ah just as a knock sounded at the door. Through the crack, they watched as a nurse entered, followed by a Division agent in plain clothes.
"Good morning, Mrs. Seo," the nurse said cheerfully. "Time for your medication."
Min-Seo's performance was flawless. She maintained the same distant, slightly confused expression Jin had grown accustomed to seeing during his visits. "Is it morning already?" she asked vaguely.
The Division agent studied her while the nurse checked her vitals. "Mrs. Seo, have you had any visitors today?"
Min-Seo tilted her head, appearing confused. "Visitors? No... only the silver people in the walls. They come and go."
The agent and nurse exchanged glances—the nurse sympathetic, the agent dismissive. This was clearly the kind of statement they expected from her.
"Your daughter signed in at reception but hasn't been recorded visiting your room," the agent continued. "Do you know where Jin-Ah might be?"
"Jin-Ah?" Min-Seo looked around vaguely. "She was supposed to come yesterday. Or was it tomorrow?"
Jin marveled at his mother's acting skill. Behind the confused facade, he could see a sharp intelligence in her eyes that had been absent for years.
The nurse prepared a syringe with a familiar pale blue liquid—the Division's standard suppressant. "Just your regular medicine, Mrs. Seo. This will help with those silver people you've been seeing."
Jin tensed, ready to intervene. If they administered the suppressant so soon after the Clarity, the interaction could be dangerous.
Min-Seo seemed to understand the danger as well. As the nurse approached with the syringe, she suddenly knocked over the water glass on her bedside table. Water and shattered glass spread across the floor.
"Oh dear," the nurse sighed. "Let me clean that up before someone gets hurt."
As the nurse set down the syringe to clean up the mess, Min-Seo caught Jin's eye through the bathroom door crack and gave an almost imperceptible nod.
The Division agent's communication device buzzed. He stepped away to answer it, speaking in low tones. Jin extended his perception, focusing on the conversation.
"...confirmed sighting at the east entrance," a voice reported. "Two subjects matching the descriptions of the Seo siblings."
"Copy that. I'll finish here and join the search." The agent turned back to the nurse. "Administer her medication and then join the security sweep. All visitors are to be detained for questioning."
Jin realized their window for escape was closing rapidly. The Network must have created the diversion they'd planned, making it appear that Jin and Jin-Ah had been spotted at another entrance. It wouldn't buy them much time.
Once the agent left, the nurse cleaned up the spilled water and reached for the syringe again. Min-Seo caught her wrist gently.
"I don't need that today," she said, her voice suddenly clear and authoritative.
The nurse frowned. "Mrs. Seo, you know your treatment schedule is very important."
"Please," Min-Seo said. "For once, I feel clear-headed. Just skip this dose. I'll take a double tomorrow if the silver people come back."
The nurse hesitated, clearly conflicted. She had worked with Min-Seo for years and seemed genuinely concerned for her welfare. "That's against protocol..."
"No one would know," Min-Seo pressed. "Please. It's been so long since I've felt like myself."
After a moment's consideration, the nurse sighed and pocketed the syringe. "Alright. Just this once. But if Dr. Lim asks during his rounds, I'm going to have to tell him."
"Thank you," Min-Seo said with genuine gratitude.
As soon as the nurse left, Jin and Jin-Ah emerged from the bathroom.
"That was impressive, Mom," Jin-Ah said with newfound respect.
Min-Seo smiled faintly. "I've been more aware than they think. The drugs... they cloud everything, but I could still hear, still understand. I just couldn't... respond properly." Her expression turned serious. "You need to leave. They're searching for you."
Jin nodded, but hesitated by her bedside. "We brought more doses of the medicine. If you can hide them—"
"Under the loose floorboard by the window," Min-Seo said immediately. "Your father taught me about hiding things from the Division years ago."
Jin-Ah quickly concealed the remaining vials where their mother indicated.
"We'll come back," Jin promised. "And eventually, we'll get you out of here."
Min-Seo touched his face gently. "Find your father first. Complete what he started." Her eyes grew distant again, but this time it seemed intentional rather than symptomatic. "The fifth point. His old office. The answers are there."
"We'll find it," Jin assured her.
Min-Seo suddenly gripped his arm with surprising strength. "Jin, listen carefully. The circuit isn't just a rescue system. Your father... he discovered something about the Threshold. Something he couldn't tell anyone, not even his colleagues. That's why he built in safeguards. That's why he encoded the key in you."
"What safeguards?" Jin asked urgently. "What did he discover?"
His mother's gaze drifted to Jin-Ah. "Your research. The notebook. The calculations you couldn't solve."
Jin-Ah's eyes widened. "My threshold mathematics project? I've been working on those equations for years, ever since Dad disappeared. I thought they were just theoretical exercises he left behind."
"They're part of the key," Min-Seo said. "Your father split the knowledge between you. Jin has the genetic key for activation; you have the mathematical key for stabilization." She looked between her children with sudden fierce pride. "He knew it would take both of you."
A distant alarm began to sound—the facility's security system activating.
"Go," Min-Seo urged. "The service elevator at the end of the hall. Maintenance uses it to avoid disturbing patients."
Jin embraced his mother quickly. "We'll be back. And we'll bring Dad home."
"I know you will," she replied with surprising confidence. "Now that I can think clearly again... I'll help from here. There are other patients like me. We talk when the nurses aren't watching. Some of us see things in the silver lines too."
Jin-Ah hugged their mother next. "Stay safe, Mom. Don't let them know you're more lucid."
"I've been playing confused for years, dear," Min-Seo said with a hint of her old humor. "I can manage a bit longer."
As they prepared to leave, Min-Seo called softly after them. "Jin. Your notebook. The one in your backpack at home. Get it. Your father left you messages there too."
Jin frowned in confusion. "What notebook? I don't—"
"The one you used to draw in as a child. The silver patterns. He knew you were seeing them even then."
Before Jin could ask more questions, the facility alarm changed pitch, indicating a security lockdown was imminent. Jin and Jin-Ah slipped out of the room, Jin focusing intently on suppressing his threshold signature.
The hallway was in controlled chaos—staff hurrying to check on patients while security personnel moved systematically from room to room. Jin guided his sister toward the service elevator, using his extended perception to navigate around approaching Division agents.
They reached the elevator just as footsteps rounded the corner behind them. Jin pressed the call button repeatedly, tension mounting as the elevator's gears groaned slowly.
"They're coming," Jin-Ah whispered.
Jin concentrated, drawing on his energy manipulation ability to speed the elevator's ascent. The silver lines connecting to the machinery brightened, and the car accelerated noticeably, arriving at their floor with a soft ding.
As they stepped inside, a shout came from down the hall. "Stop right there!"
Two Division agents were running toward them, drawing what appeared to be standard sidearms but which Jin recognized from his time in Division custody as specialized suppression weapons—designed to disrupt threshold energy rather than cause physical harm.
The elevator doors began to close agonizingly slowly. One agent raised his weapon, aiming at the narrowing gap.
Pure protective instinct surged through Jin. He thrust his hand toward the closing doors, concentrating on the silver lines around his sister. Energy flowed from his fingertips, forming a translucent silver barrier just as the agent fired.
The suppression pulse hit the barrier and scattered harmlessly in silver ripples.
SYSTEM NOTIFICATION: Ability [Barrier Creation Level 1] has awakened!
The doors closed fully, and the elevator began its descent to the ground floor. Jin sagged against the wall, suddenly exhausted.
"What was that?" Jin-Ah asked, eyes wide with amazement.
Jin wiped blood from his nose with the back of his hand. "I think I just learned how to create a threshold barrier."
"You're bleeding again."
"It happens when I push too hard with a new ability," Jin explained. "Dr. Ha says it's my brain adapting to the threshold energy."
When the elevator reached the basement level, they carefully made their way through a maintenance area and out through a loading dock. The facility grounds were swarming with security personnel, but their focus seemed to be on the east entrance—where the Network's diversion was taking place.
They were nearly to the perimeter fence when Jin sensed a familiar void in the threshold energy behind them.
"Keep going," he told Jin-Ah. "I'll catch up."
Jin-Ah hesitated. "What? No way. We stay together."
"Trust me," Jin insisted. "I need to handle this. The extraction point is behind that maintenance shed. Tae-Woo will be waiting. If I'm not there in five minutes, leave without me."
Before Jin-Ah could protest further, Jin turned to face the approaching presence. Agent Song Hye-Rin stood twenty feet away, her characteristic absence of silver lines making her appear like a hole in Jin's perception.
"Jin Hyeon," she said calmly. "I've been looking for you."
Jin positioned himself to keep Jin-Ah behind him. "I'm not going back to a Division facility."
"I'm not here to take you in," Agent Song replied, surprising him. She glanced around to ensure they weren't being observed, then lowered her weapon. "I'm here to warn you."
Jin remained tense, ready to create another barrier if needed. "Warn me about what?"
"Director Choi has authorized full containment protocols for you and your sister. The Division's official position is that your threshold sensitivity has progressed to dangerous levels." Agent Song's expression remained neutral, but her eyes conveyed unexpected urgency. "They're tracking your mother's communication devices. They knew you'd come here eventually."
"Why are you telling me this?" Jin demanded. "Why help us?"
Something shifted in Agent Song's demeanor—a subtle softening around her eyes. "I knew your father, Jin. We worked together before the Division became... what it is now."
Jin's suspicion didn't waver. "Everyone seems to have known my father. The Collector, Director Choi, now you."
"Your father was a brilliant man," Agent Song said. "But he made enemies by questioning the Division's approach to threshold research." She hesitated. "He also made promises that some of us intend to keep."
"What promises?"
"To protect his family if anything happened to him." Agent Song's gaze shifted to Jin-Ah, who was watching their exchange with wary fascination. "All of his family."
Jin studied her carefully. "You really knew him, didn't you? Not just professionally."
A flicker of something—pain, perhaps—crossed Agent Song's face. "He was my mentor. And my friend." She reached into her jacket and removed a small object, which she held out to Jin. "He would have wanted you to have this."
Jin cautiously accepted it. It was a small silver disk, etched with the same geometric patterns that marked the convergence points.
"What is it?"
"A key," Agent Song replied. "For his private research archive at SNU. The one even Director Choi doesn't know about."
Jin pocketed the disk, still suspicious. "Why help us now? You've been hunting me since the hospital breach."
"I've been tracking you," Agent Song corrected. "There's a difference." She checked her watch. "You have approximately three minutes before the security grid reactivates. You should go."
Jin hesitated. "You could lose your position for this."
Agent Song's expression remained impassive, but her words carried weight. "Your father made the same choice you're making now. Be careful it doesn't end the same way."
Before Jin could ask what she meant, alarms blared from the main facility. Agent Song turned away, drawing her weapon again. "I never saw you," she said, heading toward the commotion. "Make it count, Jin Hyeon."
Jin rejoined Jin-Ah, who had witnessed the entire exchange.
"Was that—"
"Agent Song," Jin confirmed. "And apparently she was friends with Dad."
They hurried to the extraction point, where Tae-Woo was indeed waiting with a different vehicle—a delivery truck this time.
"Cutting it close," he commented as they climbed inside. "Any problems?"
Jin thought about the strange encounter with Agent Song, the disk now secure in his pocket, and his mother's unexpected lucidity.
"Nothing we couldn't handle," he said. "But we need to make a stop before going back to the safe house."
"Where?" Dr. Ha asked from the driver's seat.
Jin met his sister's eyes, seeing the same determination reflected there. "Home. We need to get Jin-Ah's research notebook and apparently, an old drawing book of mine."
As they drove away from the facility, Jin looked back one last time. For a brief moment, he thought he saw his mother watching from her window, her hand raised in farewell. Then the truck rounded a corner, and the care center disappeared from view.
Jin turned his attention to the silver disk Agent Song had given him, studying its intricate patterns. What archives had his father kept secret, even from the Division? And why had Agent Song risked her position to help them?
Most concerning was her parting warning: Your father made the same choice you're making now. Be careful it doesn't end the same way.
What choice exactly had his father made? And how had it led to his disappearance into the Threshold?
Jin had a feeling they would soon find out.
Author's Note: The plot thickens! What do you think of Agent Song's unexpected connection to Jin's father? And what could be in those notebooks that Min-Seo was so insistent about? Share your theories in the comments!
Coming Next: Chapter 7: The Origin Point - Jin and Dr. Ha venture into Dr. Seo's former research office, where Jin activates the fifth convergence point and receives a shocking message from beyond the Threshold.