Liora did not believe in gentle lessons.
She led Kael beneath the city before sunrise, through a service tunnel sealed decades ago and forgotten by everyone except the cracks. The air down there was colder, heavier, carrying the smell of damp concrete and rusted metal. Old warning signs peeled from the walls, their letters warped, as if even language had begun to fail.
"This is where you learn properly," Liora said, her voice echoing softly. "Not in alleys. Not by accident."
Kael followed, senses stretched thin. The cracklines were everywhere here—threaded through walls, crawling along ceilings, pulsing faintly beneath the ground like veins beneath skin. Some shimmered softly. Others were dark, jagged, angry-looking.
He swallowed. "How many are there?"
Liora didn't slow. "Enough to break the city if someone lets them."
They stopped in a wide underground chamber where old rails vanished into darkness. The fractures here were thicker, more defined—some wide enough that Kael could see warped reflections inside them. Streets that bent the wrong way. People walking backward. Shadows with too many limbs.
Liora turned to him. "First rule," she said. "The crackline is not your friend."
Kael nodded. "But it helped me. It protected me."
"It reacted," she corrected. "That's not the same thing. The line responds to perception. Fear sharpens it. Confidence stabilizes it. Obsession corrupts it."
She stepped onto a glowing fracture without hesitation. It hummed beneath her boots but didn't warp.
"Second rule," she continued. "Never step onto a line unless you know where it leads—or what might notice."
Kael hesitated, then followed her onto the edge of the fracture. It pulsed beneath his feet, familiar now. Almost welcoming.
That scared him more than anything else.
Liora's eyes flicked to his shadow. It lagged behind him by half a second before snapping back into place.
"You're synchronizing faster than you should," she said quietly.
Kael stiffened. "That's bad, isn't it?"
"Yes."
She motioned for him to step off the line. He obeyed, heart thudding.
"Third rule," Liora said. "Nothing you see in the fracture is obligated to be honest."
As if summoned by her words, the darkness at the far end of the chamber rippled. Something moved—slow, deliberate. A shape peeled itself out of a crack in the wall, tall and thin, its outline shimmering like heat distortion.
Kael's breath caught.
The thing looked human. Almost.
Its face was smooth, eyes hollow, mouth fixed in a gentle smile that never reached anywhere real.
"Linewalker," it said pleasantly. "You walk like one who listens."
Kael took a step back.
Liora did not move. "Don't speak to it," she said.
The thing tilted its head. "Rude. I was only curious. The cracks whisper about you."
Kael's heart hammered. The fractures around them pulsed faster, responding to tension.
Liora raised a hand—not in threat, but warning. "Leave."
The thing smiled wider. "Soon," it said. "Not yet."
It stepped closer.
The pressure in the chamber intensified. Kael felt it in his skull, a tightening behind his eyes, like the world was pressing inward. His thoughts began to blur, edges softening.
Step onto the line, something whispered—not the creature, but the fracture itself. You know how.
Kael clenched his fists. He remembered Liora's words. Obsession corrupts it.
The thing reached out.
Liora moved.
She stepped onto a fracture and twisted.
Reality folded. The crackline flared bright, slicing the space between them. The thing recoiled with a hiss, its form blurring violently before snapping backward into the wall. The chamber fell still.
Kael exhaled shakily.
"That," Liora said, stepping back onto solid ground, "was a Listener. It doesn't hunt flesh. It hunts attention."
Kael swallowed. "It knew about me."
"Everything along the cracks knows now," she replied. "Because someone is pushing the lines harder than they've been pushed in decades."
Kael's chest tightened. "The man in the hood."
Liora's jaw set. "Yes. The Linebreaker."
She turned away, pacing. "He was once like you. Curious. Careful. Brilliant. Then he decided the cracks were meant to be shaped."
Kael frowned. "Can they be?"
Liora stopped. Looked at him.
"That's the fourth rule," she said. "Never assume the fracture's limits match your own."
The ground trembled beneath them.
Subtle. Wrong.
Kael felt it immediately—the pulse beneath his feet accelerating, overlapping rhythms colliding. The cracks began to glow brighter, threads of light weaving together.
Liora's eyes widened. "He's testing something."
"What?" Kael asked.
"Us."
The chamber shifted.
Walls bent inward. The floor sloped unnaturally, forcing Kael to brace himself. Multiple fractures merged into a single glowing seam, wide and violent.
And from it—something emerged.
This one was not subtle.
It was massive, all angles and shadow, its shape unstable, as if it were being constantly rewritten. Limbs formed and collapsed. A face flickered in and out of existence.
Kael's instincts screamed.
"Don't run," Liora snapped. "Listen."
The thing roared—not with sound, but with pressure. Kael felt it slam into his thoughts, scattering them.
He staggered.
The crackline beneath him surged.
Now, it whispered.
Kael made a choice.
He stepped fully onto the line.
The world sharpened.
Time slowed—not stopped, but stretched. He felt the fracture beneath him like a living map, every ripple, every current. He understood where it was weakest. Where it bent. Where it could move.
"Guide it," Liora shouted. "Don't fight it!"
The creature lunged.
Kael shifted—not away, but along the fracture. The line bent with him, redirecting the creature's momentum. It slammed into the wall, reality splintering where it struck.
Kael felt the strain immediately—heat behind his eyes, blood in his mouth.
But he held.
The crackline flared.
The creature howled as the fracture folded inward, swallowing it piece by piece until the chamber snapped back into place.
Silence fell.
Kael collapsed to his knees, gasping.
Liora was beside him instantly. "Enough. That was enough."
She helped him up, studying his face closely.
"You crossed a threshold just now," she said quietly. "The cracks responded to intent, not instinct."
Kael wiped blood from his lip. "I didn't even think. I just… felt it."
"That's what scares me."
They returned to the surface as the city woke, sunlight washing the streets clean of fracture-glow. To anyone else, nothing had happened.
Kael leaned against a building, exhausted.
"So what now?" he asked.
Liora looked out over the city, her expression grim. "Now the Linebreaker knows exactly how far you can go."
Kael stared at the pavement, where faint lines shimmered just beneath the surface.
"And?" he asked.
Liora met his eyes.
"And the cracks," she said, "are starting to prefer your voice."
Somewhere beneath the city, the fractures pulsed—patient, attentive, learning.
And far away, something smiled.