The boy's golden eyes hardened. With a flick of his wrist, nearly invisible threads snapped forward, fastening onto a massive tree trunk.
Shhhk!
The trunk toppled in an instant, crashing down with a thunderous crack. Behind it, a Demon Slayer Corps swordsman who had been lying in wait was suddenly exposed.
Relief flashed across Tanjiro's face.
Someone's here—!
The hope lasted only a breath. The swordsman's body convulsed. His head burst apart into fragments, his torso following, shredding into chunks of flesh that scattered across the ground like broken dolls.
The metallic stench of blood hit Tanjiro's nose all at once.
His stomach twisted. He doubled over, gagging, bile burning his throat.
"Don't tell me," the boy said, voice quiet yet cutting, "you thought he was here to save you."
He toyed lazily with the threads dangling between his fingers. "No one will save you. Not today."
With a snap of his finger, another strand lashed out. The air whistled with a deadly shriek, sharp enough to raise gooseflesh along Tanjiro's arms.
Tanjiro's instincts screamed.
He flung himself down, scraping his palms against the dirt.
Crack!
The tree he'd stood against split cleanly in two. The halves toppled with a groan, shaking the earth.
Cold sweat streamed down Tanjiro's back. If he had hesitated even a moment, he would have been sliced apart just like the other swordsman.
Panting, he steadied his grip on his Nichirin blade. I can't see the threads—but they're there. I need another way to track them.
His thoughts sparked. Smell.
He had used it before in these woods—catching the faint odor clinging to spider threads when his comrades had been puppeted. That same scent… distinct, foreign compared to the boy's body itself.
Tanjiro inhaled sharply, closing his eyes for half a beat. The threads came alive to him. Lines of reeking menace weaving toward him through the night air.
A flicker of hope ignited. If I can smell them, I can dodge them!
The boy tilted his head slightly. Tanjiro's roll had saved him again. Perhaps it had been luck, but his next motion was certain. Another thread cut down, slicing through the air like a scythe.
Tanjiro spun with a tight flip, his body rolling aside as the thread hissed past. Behind him, another towering tree trunk collapsed.
The boy's lips parted faintly in surprise. "...You can track them."
Tanjiro rose to his feet, sword ready, chest heaving.
But the boy's voice grew sharp. "Clever. But don't think dodging will save you."
His hand unfurled. Five fingers spread.
Snick!
From each digit, threads burst outward, slicing through the dark like a fan of blades.
Tanjiro's nose twitched—the smell flooded his senses. He whirled, his Nichirin sword flashing, batting aside one, two—
A sting tore across his cheek.
His blade had deflected the strike, but the thread curved, snaking unnaturally.
Blood welled from the shallow cut.
Tanjiro leapt back in alarm, rolling until his shoulders slammed against the roots of a tree.
The boy clenched his hand, his face a mask of cold amusement.
Tanjiro's chest tightened. A horrible premonition coiled in his stomach.
He spun—
Shhhhhh!
Threads thicker than before surged from both sides, weaving together in a net that glimmered faintly under the moon. The same threads that had diced the swordsman moments ago.
Too fast. Too close.
His mind blanked. He braced himself for the tearing agony—
"Tanjiro!"
The box on his back burst open. A small figure leapt out, intercepting the threads with arms outstretched.
A piercing shriek split the air. Flesh tore. Blood sprayed across the dirt.
Tanjiro froze. His world narrowed.
"...Nezuko."
Her right arm had been severed at the elbow, fragments of flesh spattering across the ground.
"NEZUKO!"
He rushed forward, catching her before she collapsed. The box straps snapped uselessly against his shoulders.
She trembled in his arms, her fanged mouth opening in a pained groan.
"Why—why would you—" His voice cracked. "Nezuko, why would you do this for me?"
For an instant, he forgot the battle, forgot the demon standing before him. His hands pressed against the stump, desperate to stop the blood.
The boy tilted his head, then smiled—not with cruelty this time, but fascination.
"Interesting. So you were hiding something like this… a treasure." His bare feet padded closer, threads trailing casually from his fingers.
Panic surged in Tanjiro.
He hoisted Nezuko into his arms and fled into the forest, ducking behind a broad trunk.
"Nezuko, hold on. Please… please…" He pressed her to him, tears prickling at the corners of his eyes.
She groaned faintly.
"What should I do? What should I do?!" His voice broke into a whisper, frantic and useless.
Then—he felt it. A shift beneath his hands.
He pulled back in disbelief.
From the raw wound at her elbow, pale flesh sprouted. Tendons stretched, bones knitted, skin wrapped whole. In moments, a new arm emerged, unblemished, unbloodied.
"Nezuko…"
Her large eyes blinked open, meeting his with a faint, affectionate gleam.
Tanjiro's relief lasted only a breath.
Because the boy was already closing in, his threads slicing through trees on either side, cutting them apart like fragile reeds.
"Fascinating," the boy murmured.
"Why protect a human? Why choose pain for their sake? You and I… are the same kind."
His words weren't aimed at Tanjiro. His gaze locked on Nezuko.
"Come. Be part of my family."
Nezuko's expression twisted. She shook her head violently, muffled growls rumbling behind her bamboo muzzle.
Tanjiro squeezed her hand tightly, grounding her, lending her resolve.
The forest grew eerily still. Not a rustle, not a chirp of an insect. Even the air seemed to hold its breath.
Tanjiro's skin crawled. Where is he?
He risked a glance around the trunk. Empty.
No sign of the boy.
He knew better than to trust it. The enemy wasn't gone—he was waiting.
The voice came from above, cool and distant.
"It seems… only if I erase you completely will she be mine."
Tanjiro's eyes shot up.
High above, the boy stood balanced on a lattice of shining threads strung between treetops, hand outstretched. His pale figure hovered in the moonlight like a Demon.
Before Tanjiro could move, the threads snapped downward.
They wrapped Nezuko in an instant, binding her arms, her legs, her body. The strands cut into her flesh, blood sliding down their sharp edges.
"Nezuko!"
She screamed as the boy yanked her upward. Her body swung helplessly, dangling like prey.
Tanjiro lurched to his feet, his blade trembling in his grip.
"Let her go!" His voice cracked into a roar. "That's my sister! Give her back!"
The boy's lips curved faintly. "Sister?" He drew the word out, dripping with mockery. Then his face hardened, all amusement gone.
"What right do you have… to call yourself her brother?"
His palm snapped open. Threads slashed outward in a fan, rushing toward Tanjiro.