At first, Iris thought it was just her upstairs neighbor.

The knocking started soft. A polite tap-tap-tap, just enough to draw her attention from her laptop screen. She paused, blinked. It stopped. Shrugging, she went back to typing up the quarterly analysis her manager said was urgent. It was always urgent. She rolled her eyes.

The next night, the knocking came again. This time, slower. Deliberate. She sat up straighter in bed, the glow of her screen making her face look hollow in the dark. She glanced at the door. Nothing. Ceiling? No. She tilted her head. That’s when she realized the sound was coming from the bathroom.

Not the wall. The mirror.

She stared. The bathroom mirror was old, one of those antique gilded things the landlord bragged about as a "charming vintage detail". Iris had always hated it. Its surface warped slightly, the glass more mercury than reflection. On most days, it distorted her just enough to unsettle her, but not enough to justify complaining.

That night, the knocking came again. Three raps. Paused. Then again, in rhythm with her own heartbeat. She stood, laptop forgotten, and walked into the bathroom. Her reflection followed her, as it always did. Same tired eyes, same cracked lips, same tight bun pulled back for the sake of being “presentable.”

But then her reflection blinked when she didn’t.

Iris froze. Her breath caught.

The reflection leaned in, eyes wide, hands flat against the glass. It looked panicked. Mute. Desperate.

Her hand flew to her mouth.

She raised her right hand. The reflection raised its left. But then it didn’t. It didn’t raise anything. It kept its palms to the glass, mouthing something.

Let me out.

Her knees went weak. She gripped the sink.

Was it sleep deprivation? Work stress? That fucking “team building” retreat?

She stared. The reflection stared back.

And for the first time, she saw it. Really saw it.

This woman in the mirror. Hair wild and free. Skin marked with tattoos Iris never had the courage to get. Her clothes were softer, stranger, beautiful and impractical. Her eyes were alive. Iris’s had been dead for years.

The knocking resumed. Louder now. Frantic.

She looked down at her hands. They were trembling. She touched the mirror.

It was warm.

The woman inside knocked once more, then shoved.

And something flipped.

There was a lurch, a pull, a tearing sensation like muscle splitting from bone. Iris stumbled backward, but the bathroom didn't catch her. She fell.

Into glass, into water, into darkness.

When she opened her eyes, the world was warped. Cold. Distant.

She screamed, but no sound came out.

On the other side of the mirror, her reflection, no, not her. The demon-skin in her shape adjusted the bun. Straightened the blazer. Smiled with red lipstick Iris never wore.

The creature turned and left the bathroom, heels clicking confidently on the floor.

And in the mirror, Iris was left behind, pressing her palms against the inside.

Tap. Tap. Tap.

But no one was listening.