The Passenger in Mercy

The three knocks came again.

They were not loud. They traveled through the wreckage with the patience of a pulse, striking the engine’s copper ribs and returning through the tower’s iron bones. Oliver felt each one in his teeth.

Nadia pushed herself upright against the tilted wall. Her face had gone gray, but the crack in her chest shone with a thin blue light. “It’s answering you.”

“I didn’t ask anything.”

“That has never stopped a machine from answering.”

The tower groaned around them. Far below, whole galleries of stone drifted upward through the broken shaft, turning slowly as if they had forgotten which way was down. Aven Marr stood near the ruined heart-machine, one hand pressed to its casing. His coat floated around him like dark water.

“Do not open the engine,” he said.

Oliver looked at him. “You told me the train was only a vessel.”

“I told you what I believed when belief was still useful.”

The gauge above the engine door flickered. WITHHELD vanished. OWNER UNKNOWN returned, its letters trembling in the glass.

Oliver found the latch.

Aven crossed the chamber in three weightless steps. “Mercy was never meant to carry a passenger.”

“Then why is someone knocking?”

Aven’s expression tightened. “Because there is always someone inside what we call an empty thing.”

Oliver opened the door.

The engine had become a room.

Not the cramped brass compartment he knew, but a long platform suspended in darkness. A station sign hung overhead, its paint peeled away except for one word: DEPARTURE. Along the platform stood hundreds of little lamps, each containing a different color of light—amber, green, violet, the dull red of banked coals. They pulsed in time with the train’s stabilizer pumps.

At the far end, beneath a clock with no hands, sat a figure in an engineer’s coat.

Oliver knew the coat. He had worn it before he remembered being Oliver Vale.

The figure’s face was hidden behind a smooth brass mask. Its hands rested on its knees. When Oliver stepped onto the platform, the figure rose.

“You came late,” it said.

Its voice was Oliver’s, but younger. Not the faceless remnant’s voice. This one carried exhaustion, and something colder beneath it.

“I came when I could.”