The black car moved slower now, winding through a quiet neighborhood lined with apartment buildings and small houses. Woo Joon kept a steady distance behind, his fingers tight on the steering wheel, eyes focused like a hawk tracking prey. The girl… she was inside that car. The same little girl from earlier—the one with the butterfly hairpin.
The vehicle finally came to a stop in front of a narrow two-story house at the far end of the street. Woo Joon parked across the road and watched.
The door of the car opened. The girl stepped out first, cautiously looking both ways. Her small frame and innocent steps made her seem even younger than ten. Beside her, a tall woman emerged from the driver's side. She wore a black face mask and a low cap that shadowed her face completely. Her hand rested lightly on the girl's back as they walked to the front door.
Woo Joon's eyes narrowed. Something about the woman's movement wasn't right—too silent, too fluid. He reached for his badge, slid it into his coat pocket, and quietly exited his car.
By the time he crossed the street, the front door had already closed.
He took a deep breath and knocked. Once. Twice.
There was no answer.
He was about to knock a third time when the door creaked open slightly. A small face peeked through.
The girl.
"Hey," Woo Joon said, forcing a gentle smile. "You remember me?"
The girl tilted her head, blinking up at him. Then her eyes lit up with recognition. "You're the man from before."
He smiled wider. "That's right. Glad you remember."
She opened the door a little wider but stayed behind it.
"So, this is your house?" he asked casually. "Looks nice. Is your mom home?"
Her smile faded. "I don't have a mom."
Woo Joon blinked. "Oh… I'm sorry to hear that. Then who was that woman who came in with you?"
The girl hesitated. "What woman?"
Woo Joon's brow furrowed. "The one who got out of the car with you."
"No one was with me," she said quickly, her voice too flat. Too rehearsed.
He leaned slightly, trying to peer past the doorway. "So, you live here… alone?"
"Ah… no! I mean… I live with someone."
"Can I come in?"
Her body stiffened. "You're a stranger. I'm not supposed to let strangers in."
Woo Joon reached into his pocket and showed his badge. "I'm not just anyone. I'm a police officer. And I'm not here to scare you—I saw you earlier at the beach, and I got worried. A… bad thing happened there today. A woman was found dead. I just want to make sure you're safe."
The girl hesitated, then stepped aside slowly, letting the door swing open.
Woo Joon entered with careful steps, scanning everything.
The living room was clean. Too clean. A candle burned in the corner, masking a faint scent of something—something… burnt?
The girl hovered by the wall as he moved inside, her eyes following him closely.
Woo Joon glanced at a couch, a small table with crayons and paper scattered across it, and a staircase leading upstairs. Everything looked normal.
Until he saw the hallway to the right.
At the end was a room with a door barely ajar. A faint sound—like breathing—came from within.
He took a cautious step toward it.
"Um… mister," the girl said suddenly, stepping in front of him. "You don't need to go in there."
Woo Joon stopped. His gaze dropped to her hands. They were trembling.
"Why not?" he asked calmly.
"That's just… storage. There's nothing in there."
"Is the person you live with in there?"
She didn't answer.
He took a step forward.
She moved again, blocking him. This time more firmly.
Woo Joon's tone sharpened. "Is someone in there who shouldn't be?"
"No," she whispered. "Please don't go in."
Woo Joon leaned down so their eyes met. "Hey. You don't have to protect anyone. If there's something wrong, I can help."
She looked away, eyes filled with panic.
Woo Joon's instincts screamed.
He stood straight and reached for the door.
Suddenly, the air shifted.
Behind that door… something was waiting.
Something that wasn't human.
Woo Joon slowly pushed the door open.
The air inside was thick and strangely cold. The curtains were drawn, casting the room into dim shadow. On the bed lay a woman, pale and motionless, her chest barely rising and falling.
Woo Joon stepped closer. "Who is this?"
The little girl lingered in the doorway. "She's just sick… we were coming back from the hospital. That's probably the woman you saw me with earlier. She's going to be fine."
Woo Joon narrowed his eyes. The woman on the bed had long black hair that spilled over her pillow like ink. But earlier… he had seen the woman with a short bob under that cap. He was certain.
Something didn't add up.
"You said she was the one with you earlier," he said. "But her hair—"
"She wears a wig sometimes," the girl cut in quickly, her voice a little too sharp. "And she doesn't like strangers staring at her."
Woo Joon looked at her. She was nervous. Too nervous. But pressing too hard might scare her off.
"I understand," he said gently. "But I have to ask more questions. Where's your father?"
The girl lowered her head. "He's dead."
Woo Joon's gaze softened. "I'm sorry. You said earlier your mom wasn't around."
"I lied… I didn't know you," she whispered. "I'm sorry."
"I get it." He nodded slowly. "But still, someone has to take care of you. You're still a child."
The girl's voice grew quiet. "I can't go to school. If I leave, mom will be alone. And… my older sister works a lot. She takes care of us both."
Woo Joon raised an eyebrow. "You shouldn't have to handle this alone. I'm worried about you."
Suddenly, from deeper inside the house—a sound.
A weak thud. A faint moan.
It came from behind the second door within the same room.
Woo Joon froze.
The little girl did too.
He turned toward the door. "Who's in there?"
The girl's face went pale. "No one. It's just storage."
He stepped forward slowly. Another faint sound. A whisper, barely audible—"Help…"
Woo Joon reached for the doorknob.
The girl's hands trembled. "Please don't…"
His fingers touched the knob, but before he could turn it—
His phone rang.
He quickly stepped back and checked the screen. It was from Hae In's school.
His breath caught. "Hello?"
The voice on the other end was tense. "Mr. Woo Joon, this is Hae In's teacher. She's been in a fight… we need you to come right away."
His heart clenched. "I'll be there."
He looked at the girl. "I have to go… but I'll be back. Understand?"
She nodded, eyes wide.
Woo Joon stepped out of the house, one last glance at the mysterious door haunting his mind. As he drove away, he couldn't shake the image of that hidden room.