Oil lamplight flickered across unfinished mission reports as Tanjiro stared at blank paper, brush poised but motionless.
How did you describe something that shouldn't be possible? How did you document violations of everything you'd been taught about demon nature?
"Enter."
He looked up as Tengen slid the door open, the former Sound Hashira's cane tapping against wooden floors.
"Working late?"
Tengen settled across from him with careful movements that spoke of old injuries and hard-won wisdom.
"Trying to find the right words."
Tanjiro set down his brush, grateful for the interruption.
"How do you describe something that shouldn't be possible?"
"Start with what you observed, not what you think it means."
"Three demons. All docile after Akira spoke to them. No violence, no struggle."
His fingers drummed against the desk, nervous energy seeking outlet.
"It was like they were waiting for her."
"Waiting?"
"They knew her, Tengen-san. Spoke to her like old friends."
The memory made his scar throb with warning.
"That's not normal demon behavior."
"No," Tengen's voice carried the weight of years spent hunting creatures that defied explanation, "it's not. What else?"
"Her scent changes when she uses her techniques. Becomes metallic, cold."
The description sounded insane even to his own ears.
"And the demons disappear completely. No trail, no trace."
"Interesting."
Tengen leaned forward, lamplight casting deep shadows across his scarred features.
"I've been making inquiries about our new Hashira. Found some discrepancies in her story."
"What kind of discrepancies?"
"The kind that suggest we need to watch her very carefully."
Tengen's remaining eye fixed on Tanjiro with unusual intensity.
"Villages she claims to have saved have no memory of demon attacks. Some remember strange incidents—people disappearing, then returning with no memory of where they'd been."
"Survivors of demon attacks?"
"Or something else entirely."
Tengen's fingers tapped against his cane in thoughtful rhythm.
"Witnesses describe her techniques, but their stories don't match. Like their memories were edited."
"Edited how?"
"Key details missing. Fuzzy recollections."
The former Hashira's voice dropped to barely above a whisper.
"But they all remember feeling completely calm during what should have been terrifying encounters."
The pieces clicked together in Tanjiro's mind like tiles in a puzzle he didn't want to complete.
"You think she's manipulating memories?"
"I think we're dealing with something unprecedented. Someone with abilities that don't fit normal categories."
Tengen met his gaze steadily.
"The question is whether those abilities serve our purposes or someone else's."
"What do we do?"
"Gather more information. Discrete inquiries only."
Tengen rose carefully, his cane bearing weight that should have been distributed across two healthy legs.
"And watch her closely. If she's what I suspect, she's more dangerous than any demon we've faced."
"More dangerous how?"
"Because she makes you want to trust her."
The weight of that revelation settled over them both as Tengen prepared to leave, but his words had opened floodgates of doubt that Tanjiro knew would keep him awake long into the night.
---
"Nezuko?"
Tanjiro slid her door open gently, concern sharpening his voice as he noticed her pallor.
"Are you feeling alright?"
"Just tired, brother."
But her voice carried a tremor that hadn't been there that morning, a fragility that made his protective instincts flare.
She knelt by her window, staring out at the darkening courtyard with unusual intensity.
"You look pale. Should I call for a doctor?"
"No! No, I'm fine."
Her response came too quickly, too sharp, like denial of something she couldn't afford to acknowledge.
"Just... strange dreams lately."
"What kind of dreams?"
Nezuko's fingers traced patterns on the windowsill—patterns that looked disturbingly like claw marks gouged into wood.
"Voices calling to me. Familiar voices, but I can't remember from where."
"Since when?"
"Since she arrived."
Nezuko's reflection in the window glass seemed to flicker between human features and something subtly wrong.
"The new Hashira. There's something about her that makes my skin crawl."
"Akira-san?"
Tanjiro moved closer, noting the way his sister's eyes seemed to catch and reflect lamplight with unusual intensity.
"Has she done something to upset you?"
"Not done. It's what she is."
Nezuko turned from the window, and for just a moment, her eyes reflected the light like polished amber.
"Brother, what if being human isn't the only choice? What if there's something in between?"
The question hung in the air like incense, heavy and disturbing in ways he couldn't articulate.
"What do you mean?"
"I don't know. That's what frightens me."
Nezuko's voice dropped to barely above a whisper.
"In my dreams, there are others like me. Others who changed but didn't... finish changing."
"Dreams are just dreams, Nezuko."
"Are they? Or are they memories I was never supposed to keep?"
Before he could respond, she turned back to the window with sudden alertness, her body language shifting to something predatory and alert.
"Someone's moving in the courtyard," she said. "Moving wrong."
Tanjiro joined her at the window, following her gaze to the moonlit space below.
At first he saw nothing, just empty stone and familiar shadows. Then movement caught his eye—a figure in Corps uniform crossing the yard with fluid grace that no human should possess in darkness.
"Auburn hair," Nezuko breathed. "She's leaving headquarters."
"Where would she go at this hour?"
"Somewhere she doesn't want witnesses."
They watched in silence as the figure disappeared into mountain paths that led away from human settlements, moving with purpose that spoke of secret destinations and hidden agendas.
"Should we follow her?" Nezuko asked.
"Not tonight. But tomorrow..."
Tanjiro's jaw tightened with resolve.
"Tomorrow we get answers."
The moonlight streaming through their window seemed colder now, carrying with it the scent of something metallic and wrong that neither sibling could quite identify, but both instinctively feared.