The moment they stepped into Kaya's mansion, Rex could feel it.
The air.
It was clean… but heavy.
The walls were quiet… too quiet.
The tea smelled sweet… but there was something behind it.
He didn't flinch. He didn't speak.
But [Michael] hummed low inside him.
[…Foreign compound detected. Mild toxin present in tea leaf infusion. Ingestion over time causes organ fatigue, visual blurring, and increased susceptibility to fevers. Dosage minimal but consistent. Source: manually prepared. Servant route confirmed.]
Rex kept his gaze fixed on Kaya as she sipped from the porcelain cup.
She looked delicate. Pale skin, soft brown hair, eyes half-lidded with exhaustion. She smiled kindly at Usopp, who sat beside her on the bed, telling yet another story about fighting sea kings with a slingshot.
She laughed.
Softly. Gently.
But there was pain behind her eyes.
Kaya wasn't acting.
She was slowly dying.
And no one knew.
"Would you like some tea?" she offered sweetly, looking to Luffy, Zoro, and Rex.
Zoro shook his head with a grunt. "Pass."
Luffy had already grabbed two cookies and was trying to chew both at once.
Rex stepped forward and gently accepted the cup.
"Thank you," he said softly, sitting beside her.
Nami watched him closely from behind.
Kaya smiled at him. "You're very calm."
Rex nodded, lifting the cup.
He let the aroma reach his nose. It was subtle — only a faint edge of something sharp, almost metallic. He tilted the cup just slightly and let the liquid swirl.
[…Trace amounts of Leafroot Powder mixed with old Bellbane shavings. Natural in appearance. Poisonous in combination. Estimated administration period: one month. Symptoms match host condition.]
His eyes shifted briefly to Klahadore, who stood silently near the door with hands folded.
Rex lowered the cup and gave Kaya a warm look.
"I've traveled a lot. You learn to stay calm when the world isn't."
Kaya smiled again. "You speak like someone much older."
Rex didn't answer.
He turned slightly and nodded to Nami.
She knew what that meant.
After a short visit, they left the room and walked slowly through the stone hallway, Klahadore leading them out.
"You're lucky Miss Kaya is kind enough to receive travelers," he said without turning. "But your stay should be short. Pirates bring chaos."
Rex stared at the back of his head in silence.
Every fiber in his being was ready to attack.
But he wouldn't.
Not yet.
They had no proof. No confession. No opening.
Just suspicion.
And that wasn't enough — yet.
Outside, later that evening
They sat under the trees behind the mansion. The breeze whispered through the branches, and the stars had begun to shimmer above them.
Usopp paced back and forth.
"You're saying Kaya's being poisoned?! That's impossible! She's just… she's just sick."
"No," Rex said firmly. "She's not. And you know it."
Usopp froze.
"I've known her my whole life," he said softly. "She used to run in the fields. She'd laugh so loud the neighbors would complain. She's never been weak… not until last year."
Rex stood.
"Then help me prove it."
Usopp's fists clenched.
"I'm just a liar with a slingshot. You think people will listen to me?"
"I'm the same," Rex said.
That caught everyone off guard.
"I talk big. I stand tall. But inside, I'm fighting to stay ahead of something I don't understand. Every day, I feel like I'm walking through fog."
He looked at Usopp.
"But I don't stop. And neither should you."
Usopp looked into Rex's eyes, and for the first time since meeting the crew… he believed him.
"…Okay."
Nami smiled faintly from the side.
"He's getting good at that."
Zoro nodded. "He's already better than you."
"I HEARD THAT!" Luffy shouted from up a tree.
That Night — Back at the Mansion
Rex moved silently through the courtyard. His boots made no sound. His shadow bent around corners.
[…Phantom Drift engaged. Air-step efficiency optimized. Grav-Shift adapting for rooftop traversal.]
He floated slightly above the ground, his body moving like water over the stones.
He passed the kitchens.
A dim glow. A faint smell.
He waited.
Klahadore appeared.
He was alone.
He poured something from a vial into a teapot — just a drop. Barely a blink of effort.
Then he turned and walked back toward Kaya's wing.
Rex's heart slowed. His breathing stopped.
His mind sharpened.
[…Confirmed. Hostile action against Lady Kaya. Lethal intent increasing. Poison compound adjusted. Estimated terminal dosage within one week.]
That was it.
The truth.
The butler wasn't a servant.
He was a killer in disguise.
And the final mask was about to fall.
Next Morning
Kaya sat by her window, looking out over the garden.
She smiled gently as she watched the sun rise.
But her body was weak.
She dropped her cup — trembling — as her breath caught in her throat.
Usopp rushed in. "Kaya?!"
She looked up at him, pale.
"I… I don't feel right."
Luffy and Nami rushed in behind him.
Zoro stepped in a second later, swords drawn.
And Rex entered last — slow, calm, deadly.
Behind them, Klahadore stepped in from the hall, adjusting his glasses.
"Oh my. What a mess. Has her condition worsened again?"
Usopp turned slowly.
Rage and fear burned in his eyes.
"You…"
Rex stood between them.
"I saw you last night," he said. "You poisoned the tea. You thought no one would notice."
Klahadore didn't react.
But his eyes turned sharper.
Colder.
And then…
He smiled.
"So… the mask cracks," he said. His voice shifted. His posture changed.
Even his glasses glinted more sharply.
"You really are dangerous, boy."
Rex took one step forward, his blue eyes glowing faintly.
"So are you… Kuro."
Klahadore's smile vanished.
The room went still.
Luffy's jaw dropped.
Zoro's grip tightened.
Usopp whispered, "No…"
But Rex was calm.
Because now… it was war.
And no mask would save a murderer from the storm he had just awakened.