Name: Han Soo Ah
English name: Rose
Age: 28
MBTI: ENFP
HEIGHT: 5 feet 7 inches
Occupation: Neurologist
Secret Identity: Serial killer known as The Crimson Thread
Appearance:
Elegant and meticulous. Long, platinum-blonde hair. Wears wire-rimmed glasses that give her an air of calm intellect. Her poised, professional demeanor masks something far more sinister beneath.
Personality:
Brilliant, composed, and emotionally detached
Obsessed with control—of the mind, the body, and fate
Fascinated by the connection between morality and brain function
Charismatic but manipulative
Cold empathy—she understands emotions.
Modus Operandi:
Uses surgical precision—kills leave almost no trace
Often targets individuals whose brain scans she secretly accessed through hospital connections
Leaves behind a single strand of crimson thread, symbolizing the fragile connection between life, thought, and death
Strengths:
Genius-level intellect
Expert in neurosurgery and neuropsychology
Fluent in deception and manipulation
Almost clinically emotionless during kills
Weaknesses:
Obsessive need for control
Haunted by the idea that she might lose her own mind
Has formed an unhealthy obsession over someone.
______________
She sat with legs crossed in her grandfather's office, her back straight against the antique chair. The ticking of the old brass clock behind her pulsed like a heartbeat.
He was late. Of course he was.
She traced the edge of her glove with one finger, her mind drifting to the last time she had seen Ethan— when she confessed her love.
A creak echoed in the hallway—her spine straightened. Footsteps, casual and confident. Not her grandfather's limp.
No. It couldn't be—
The door opened.
Ethan.
"You weren't supposed to be here," he said finally, stepping in and letting the door click shut behind him.
"I could say the same," she replied, her voice soft, crisp.
"Well I have already talked with your grandfather about you. He will make sure that you don't cross my path"
Soo -ah laughed like he had said a joke.
Than She smiled faintly—half elegance, half threat and said "Define well."
She passed him, stopping just beside his shoulder. Her voice dropped to a whisper.
"But if you're here to chase me, Ethan… just know I've stopped running."
She left the room, heels clicking against the marble floor like a metronome of slow doom.
___________________
Ethan also didn't waste his time. He left the office. As he was driving the car he couldn't stop thinking about soo-ah. He knew that soo-ah is doing all of this for money and fame. He has deal with many person like soo ah who are only after his money and nothing else.
But she feels different. There is something that he doesn't know.
few days ago he told his assistant to find a serial killer who was killing all the high profile person. Something triggered him that's why he wants to know about him. He wants to find his brother's murderer.
________________
The lab was dark, except for the glow of the screens.
Ethan stood motionless, staring at the monitor. File after file. Victims. Timelines. Brain scans. Autopsy photos with annotated overlays. Red string not on a board, but digitally coded, traced through neural patterns and MRI anomalies.
And then—the trigger.
Subject: Crimson Thread – Behavioral Mapping Notes
Signature: Left anterior temporal incision – clean, surgical, consistent across all victims.
All victims had abnormal amygdala structure—linked to violent impulses.
Pattern suggests… medical specialization. Neurosurgery.
He scrolled further.
Operator suspected: Han Soo Ah.
He didn't blink.
His hands didn't tremble.
He closed the file slowly, then turned around—and there she was, leaning against the frame of the glass door, watching him.
"You are so quick to find this," she said quietly.
Ethan studied her like one studies a rare, intricate weapon. He didn't speak. Just approached.
"Are you not surprised,"
"No," he said at last. "I'm not."
He tilted his head, voice measured and cool. "I've spent years chasing killers who left chaos behind. You left… order."
She smiled slightly. "That's what made me curious about you. You see structure. Even in blood."
He circled the desk, eyes never leaving her.
"You identified patterns in neurological behavior I didn't think anyone in the field had the nerve to act on," Ethan said. "You don't kill randomly. You kill… like a correction algorithm."
Do you disapprove?"
He paused.
Then shook his head. "No. I'm… impressed. You acted like a fool when we first met but you are a different person. "
"I don't approve of what you did," Ethan said. "But I can't ignore the precision. The control. The data behind every strike. You didn't lose control. You executed purpose."
He stepped closer, until they were only inches apart.
" Are you going to work with me?" he asked. Than he said
"I want the man who ordered my brother's death. And if your mind is the sharpest blade to cut through this city's rot... then I'll use it."
"But know this," he added, "I'll be watching you. If you ever slip... I'll be the one to stop you."
She smiled—not out of arrogance, but relief.
"That's the closest thing to love I've ever heard."
__________________
The room was quiet again—like always between them. But something had shifted. A charge in the air, subtle but undeniable.
Ethan stood by the window, watching the blurred lights of Seoul flicker through the rain-soaked glass.
"I need your help," he said, his voice low and firm. "The man who had killed Jin… he's in the city. Protected. Hidden behind people I can't reach."
He turned to her, watching her reaction.
"You see what others don't. You connect patterns no one even knows exist. I can't do this without you."
Soo Ah studied him for a moment, then stood from her chair with a slow, calculated grace.
"I thought you'd ask," she said. "But you know my rules."
"I expected a price," Ethan replied. "Name it."
She walked over, stopping just short of him. Her voice softened, unusually gentle. "Marry me."
His expression didn't change. "So I give you my name, and you give me the keys to your underworld?"
"Partly," she said. "If I marry you, my grandfather's business will be save in your hand as I am no good in business."
"That's all?" Ethan asked.
There was a pause. The kind that stretched a little too long.
Soo Ah looked up at him, and this time her mask cracked just enough. Her voice dropped to a whisper, almost vulnerable beneath its edges.
"And maybe… because I like you."
Ethan blinked.
"You what?"
She didn't look away. "Not in the way people like each other. I don't do hearts and flowers, Ethan. But I admire you. Trust you. You're the first person who saw me fully… and didn't flinch. And maybe the only one who could ever make me hesitate."
She stepped closer.
"I don't want to belong to a legacy I hate. I'd rather belong to someone who saw my darkness—and chose not to run."
She understood him.
And he, disturbingly, understood her.
"This wouldn't be a marriage," he said quietly. "Not in the traditional sense."
Soo Ah nodded. "No vows. No expectations. Just a shared name. And something… almost like loyalty."
He studied her. Then offered his hand.
"Then it's a deal."
Soo Ah took it, her fingers cool, her smile faint—but real.
"Congratulations, husband."
And for the first time, Ethan felt something strange tighten in his chest. Not fear. Not guilt.