Episode 1. Fault Alert from a Sealed Station

At 11:47 p.m., a single red warning appeared in the middle of the metro control room's night panel.

[MUYEONG STN / ELEVATOR B4 / DOOR OBSTRUCTION]

Seo-jin stopped moving.

Muyeong Station had been sealed eighteen years earlier. After the flood, the platforms were blocked off and the line map was redrawn around the redevelopment zone. These days the station barely existed as a name. Yet now a fault alert had risen from a dead station, and from an elevator level that was not supposed to exist.

Her coworker suggested ignoring it. Ever since night staffing was reduced, abandoned facilities occasionally sent stray sensor noise into the system. But once Seo-jin opened the detailed view, she could no longer dismiss it so easily. The last approver listed in the log was her father.

Han Dong-ho.

He had been Muyeong's last station master. Even when he was alive, he always stiffened whenever anyone mentioned B4. Muyeong only went down to B3, he used to say. There was nothing below it. He had repeated that all through Seo-jin's childhood. Now his name was attached to a maintenance alert three years after his death.

She stopped by her apartment after her shift. The bottom drawer by the entryway still held the box of things her father had left behind: a half-rusted station key, an old platform whistle, a brass employee pass whose authority had long expired. She took the pass with the Muyeong logo pressed into it. No one was there to tell her not to.

The entrance to Muyeong now looked like the back fence of a city park. The sign had been removed and a closure notice clung to the shutter. Yet the card reader had not died. When Seo-jin held the brass pass near it, the machine woke with a small tremor and the locked service door released.

The air below ground was colder and wetter than outside. At the bottom of the dark stairs, a single elevator stood lit. The panel only showed B1, B2, and B3, but when she scanned her father's pass again a black window opened beneath them.

B4

She could not press it at first. A floor her father had denied was now glowing in front of her with the same name that had appeared in the control-room alert. At last she touched the button. The elevator sank more slowly, and much farther, than it should have. Below B3 the floor indicator became a single dot and the cables groaned like something breathing in the wet dark.

When the doors opened, the first thing she saw was not rail.

It was a row of benches.

B4 was not a normal platform. Yellow tactile strips still ran along the edge, but behind them the floor had been turned into a waiting hall. Folding chairs. Small suitcases with handwritten name tags. Bundled blankets wrapped in vinyl. And across the far wall, a black electric board.

At the top of it, faded lettering still remained.

[UPBOUND WAITING REGISTER]

Some names were already dark. Some flickered weakly. One line at the bottom burned with eerie clarity.

Seo Ha-neul / 05:10 / waiting for upbound

An old station chime rang through the platform speakers. Then a voice came through, one Seo-jin knew too well.

"If you came alone, good. Don't report this to control yet."

It was her father.

She jerked her head up. No one stood there, but the voice was unmistakable. Recorded, yes, but still carrying the same dry gentleness he used when peeling tangerines at the kitchen table.

"What's left on this floor isn't broken equipment. It's the names that never made it back above ground. Open locker forty-four first."

A burst of static. Then the voice again.

"And Seo-jin. The upbound button doesn't revive anyone. It sends the record back where it belonged."

When the message ended, a row of storage lockers beneath the board lit up at once. Only number 44 glowed yellow.

Seo-jin stood there with her hand suspended in the air. B4 was real. Her father had known it, and he had expected her to come down here one day. If she reported the alert as a sensor fault, this level would be sealed again. But as long as 05:10 was still alive on that board, she could not force it into the category of harmless malfunction.

She slid her father's pass into locker 44.

The latch clicked.

A narrow paper box and a flashlight slid forward into her hands. On top of the box, written in thick black pen, was a single line.

Read the first name as a person, not as a register.

Holding the box against her chest, Seo-jin looked toward the darkness beyond the far end of the platform. Past the place where tracks should have been, dim emergency lights continued into a maintenance tunnel. Somewhere at the other end, a machine chimed again.

[ARCHIVE PURGE SCHEDULED / 05:30]

Muyeong's night was not over yet.