Sleep had become Zenitsu's enemy.
He pressed his palms against his ears, trying to muffle the symphony of night sounds that hammered against his consciousness.
Wood settled in the headquarters walls with tiny creaks. Wind whispered through roof tiles. A mouse scurried between floor joists three rooms away.
His enhanced hearing catalogued every sound with merciless precision, refusing to grant him the silence normal people took for granted.
"Just breathe," he whispered to himself, the words lost in the darkness of his quarters. "The war's over. Everyone's safe."
But safety felt like the cruelest lie of all.
During the war, threats had faces—demons with claws and fangs that his senses could detect from miles away. Now danger might wear human skin, might speak with friendly voices, might sleep in the room next door.
His hypervigilant mind conjured enemies from every shadow.
A floorboard groaned in the eastern wing. Zenitsu's body went rigid, ears straining toward the sound.
Just the building settling, his rational mind insisted. Old wood expanding and contracting with temperature changes.
Then he heard something that made his blood freeze.
Whispers.
Human whispers, pitched so low they barely registered as sound. His enhanced hearing isolated the frequency, traced it to its source—Akira's quarters, two buildings over.
The cadence was unmistakable: conversation. Question, pause, response, pause, another question. The rhythm of two people speaking in urgent, hushed tones.
Zenitsu sat up slowly, bare feet finding the cold floor. His heart hammered against his ribs as he crept toward his door, moving with the silence his training had drilled into him.
The whispers continued, just below the threshold of normal human perception.
"The eastern approach worked perfectly."
Akira's voice, unmistakable despite the low volume. A pause, as if listening to response.
"Yes, Tanjiro suspects nothing."
Another pause.
"Three more positioned by month's end."
Positioned? Three more what?
Zenitsu pressed himself against his doorframe, every muscle tense. His supernatural hearing mapped the sound with surgical precision—single location, consistent distance from his position, definitely Akira's vocal patterns.
But something was wrong. He could detect only one heartbeat, one breathing pattern, one set of micro-movements that indicated human presence.
If Akira was having a conversation, where was the other person?
The whispers stopped abruptly. Silence stretched across the compound like a held breath.
Zenitsu's enhanced senses screamed warnings he couldn't understand—the sudden quiet felt predatory, like a hunting cat freezing before the pounce.
He had to know.
Bare feet silent on wooden walkways, Zenitsu crept through the maze of buildings that comprised Corps headquarters. His hearing guided him with invisible threads of sound—Akira's steady breathing, the whisper of fabric against fabric, the soft rustle that suggested movement within her quarters.
Still only one heartbeat. Still only one person's worth of sound.
Logic warred with his enhanced senses. Maybe she'd been talking to herself. Maybe stress had made her develop peculiar nighttime habits. Maybe his post-war anxiety was making him hear conversations where none existed.
But the pauses had been too deliberate, too precise. The rhythm too perfect for soliloquy.
Soft footsteps approached Akira's door from inside. Zenitsu froze, realizing with sick certainty that she'd detected his presence.
His enhanced hearing might be superhuman, but hers was trained sharp enough to notice someone lurking outside her quarters at two in the morning.
The door slid open before he could retreat.
"Zenitsu-kun?"
Akira stood in her doorway, dressed in simple sleeping clothes that somehow managed to look elegant. Her heartbeat was slightly elevated but controlled.
Most disturbing of all, she didn't seem surprised to find him there.
"Is everything alright?"
"I heard voices." The words tumbled out before he could craft a more diplomatic approach. "Thought someone might be in trouble."
"Just me, I'm afraid."
Akira's smile carried perfect warmth, but something in her vocal undertones made his skin crawl.
"Sometimes I have trouble sleeping. Would you like to sit? I was about to make tea."
His enhanced hearing analyzed every micro-expression in her voice—a slight tension on certain syllables, practiced smoothness that suggested rehearsed explanations.
But doubt crept in despite the evidence. What if he was wrong? What if post-war stress was making him paranoid about innocent behavior?
"I don't want to intrude—"
"You're not."
Akira stepped aside, gesturing him into her quarters with genuine-seeming hospitality.
"Honestly, I could use the company."
The room was immaculate, arranged with the precision of someone who valued control over comfort. A low table sat between cushions, papers neatly stacked in one corner, her nichirin blade displayed on a wooden stand.
Everything spoke of discipline and careful order.
Everything except the lingering scent of something that didn't quite belong.
Akira knelt beside a small brazier, her movements graceful as she prepared tea with practiced efficiency.
"I was praying," she said without prompting. "My family... I speak to them sometimes when sleep won't come. The silence gets overwhelming."
Zenitsu settled across from her, watching steam rise from the kettle.
"But it sounded like you were having a conversation. With pauses and responses."
"Memory fills in the silences."
Akira's voice carried perfect grief, the kind of pain that should have resonated as genuine. But Zenitsu's enhanced hearing detected subtle discrepancies—micro-fluctuations in her heartrate during specific topics, slight vocal cord tension when mentioning her family.
"I imagine what they'd say back. What advice they'd offer."
The lie patterns were unmistakable to his supernatural senses, but his conscious mind rebelled against the evidence. Akira was a fellow Hashira, a trusted ally.
The idea that she might be deceiving him seemed absurd.
"Your voice sounds different when you talk about them," he said carefully.
"Loss changes how we speak about the people we've loved. Makes everything heavier."
"No, not heavier. More... careful. Like you're choosing each word."
Akira's cup paused halfway to her lips, the movement so brief he might have imagined it.
"Grief requires precision, Zenitsu-kun. Some pain is too raw for careless words."
Before he could respond, she shifted the conversation with surgical skill.
"But what about you? These sleepless nights—they've become a pattern, haven't they?"
The deflection was smooth, caring, impossible to challenge without seeming rude. Zenitsu found himself nodding despite his suspicions.
"Everything feels dangerous now. Even safe places."
"The war changed all of us."
Akira's voice carried what seemed like authentic understanding.
"Some wounds don't heal just because the fighting stops. Your enhanced hearing must make it even worse—all those sounds, all that information pressing against your consciousness."
"It's hard to turn off."
The admission slipped out before he could stop it, drawn by her apparent empathy.
"And stress can make us hear things that aren't there. Interpret innocent sounds as threats."
Akira spoke with the authority of someone who understood superhuman abilities.
"Our minds create patterns from chaos, especially when we're afraid."
Doubt bloomed in Zenitsu's chest like poison flowers. What if she was right? What if his post-war anxiety was making him paranoid, turning innocent behavior into sinister conspiracies?
His enhanced senses had always been reliable, but trauma could distort perception.
"Trust your instincts," Akira continued, "but don't let them consume you. Sometimes the most courageous thing is to choose peace over vigilance."
The philosophy sounded reasonable, wise even. But something in her heartbeat pattern suggested performance rather than genuine concern.
The subtle tells were there—micro-pauses before certain words, breathing rhythms that indicated deception rather than compassion.
But now he doubted his own ability to interpret those tells.
"I should let you get back to your prayers," Zenitsu said finally, rising from his cushion with uncomfortable awareness of how long he'd been there.
"Thank you for checking on me."
Akira walked him to the door, her smile carrying perfect gratitude.
"It means a lot to know friends care enough to investigate strange sounds."
"If you need anything—"
"Just knowing you're listening out for all of us is enough."
The dismissal was gentle but firm. Zenitsu bowed politely and retreated into the night, more confused than when he'd arrived.
As her door slid shut behind him, his enhanced hearing caught the subtle sound of her heartrate returning to normal—not the pattern of someone who'd been genuinely distressed, but of someone who'd successfully completed a task.
The contradiction gnawed at him as he retraced his steps through the compound. What he'd heard earlier had been unmistakably conversation—the pauses too deliberate, the rhythm too precise for soliloquy.
But what he'd found was a solitary woman claiming to speak with memories of the dead.
One of those things had to be wrong. Either his supernatural hearing was failing him, or Akira was lying with masterful skill.
Halfway back to his quarters, a new scent touched the night air—faint but deliberate, as if someone had tried to mask it without complete success.
Not human, not quite demon, but something that triggered every instinctive alarm his enhanced senses possessed.
The trail was subtle but undeniable, leading away from the compound toward the forest beyond. Something non-human had been near Akira's quarters recently, something that had left traces only supernatural senses could detect.
Zenitsu stood at the crossroads between curiosity and caution, between trusting his abilities and accepting rational explanations.
His post-war anxiety whispered that investigation would only lead to deeper paranoia, that reporting suspicions without concrete proof would make him seem like a madman driven by stress-induced delusions.
But his enhanced hearing had never lied to him before.
Back in his quarters, Zenitsu lay staring at the ceiling as questions multiplied like demons in the dark.
Had Akira been talking to someone else—someone whose presence his senses somehow couldn't detect? Had his post-war trauma finally broken his ability to distinguish between reality and paranoid fantasy?
Or had he stumbled across something that required investigation despite the risk of appearing insane?
The smart choice was to stay silent, to observe quietly rather than voice suspicions that might destroy friendships over misunderstandings. The safe choice was to assume his stress-damaged mind was creating conspiracies from innocent behavior.
But Zenitsu had learned during the war that smart choices and safe choices weren't always the right choices.
"Maybe I'm losing my mind," he whispered to the darkness. "Maybe stress is making me hear things. But maybe... maybe I should keep listening."
Sleep remained elusive as dawn approached, but for different reasons now. Instead of being haunted by random night sounds, Zenitsu found himself cataloguing every noise with new purpose.
His enhanced hearing had detected something wrong, something that deserved investigation despite the personal cost.
He would watch. He would listen. And he would gather evidence before deciding whether to trust his abilities or his doubts.
The compound settled into pre-dawn quiet around him, but Zenitsu's vigilance had found new focus.
Whatever was happening in the darkness, whatever secret Akira was hiding, his supernatural senses would eventually reveal the truth.
Even if that truth destroyed everything he thought he knew about safety, friendship, and the people he trusted with his life.