The sky tore at exactly 04:17:33 GMT.
Cass Calder heard it happen before he saw it— a sound like every radio on Earth being unplugged at once. One second the emergency shelter's loudspeaker crackled with the BBC's final bulletin; the next, the word "evacuate" winked out of existence. Not the voice— the word. The air felt suddenly lighter, as if the syllables had carried mass.
He pressed the stopwatch on his wrist.
00:00:01. The count had begun.
Outside the shelter's porthole, downtown London was unraveling in neatly labeled strips. Color went first: the red double-decker buses drained to grayscale, then to nothing, leaving only outlines. The outlines peeled away like film stock, revealing a matte black that hurt to look at. Where the black touched, glass didn't shatter— it simply forgot to be transparent. Gravity hiccupped; a police constable floated upward, mouth open in a scream that produced no sound because air friction had just been deleted.
Cass's tablet still showed the evacuation route. Then the blue line on the map pixelated, letters rearranging themselves into static snow. A single line blinked:
> EASTBOUND ONLY. OBSIDIAN EXPRESS. BOARD IN 7 MINUTES.
He didn't question it. When reality blue-screens, you follow the only prompt left.
The shelter's main door refused to budge— the concept of hinges had vanished— so Cass kicked out the porthole glass and crawled through. The shard edges should have sliced his palms, but they slid off like warm butter. No blood. Blood apparently needed viscosity. Another casualty.
He ran.
Piccadilly Circus was a silent diorama. Pigeons hung mid-flap, frozen because lift had been voted out. A tourist couple took a selfie with emptiness where their faces should have been. Cass kept the stopwatch in his peripheral vision: 00:02:11. Three minutes left.
Then he heard the whistle— a chord that existed in four octaves at once, the way cathedral bells might dream. Through the fog of un-reality, metal screeched against metal that wasn't there. A locomotive phased into being, car by car, as if someone were dragging it out of an unseen dimension. Matte obsidian plating, windows like liquid starlight, the number 0-13 stenciled on its flank in shifting glyphs.
Doors hissed open. Warm air spilled out— air that still remembered heat. A conductor in a charcoal greatcoat stood on the step. No face, just a porcelain mask cracked in the shape of an hourglass.
"Ticket," the mask said, voice layered like overlapping recordings.
"I don't—"
The conductor pressed a gloved finger to where its lips should have been. From inside the coat it drew a blank slip of cardstock and held it out. When Cass touched it, electricity snapped up his arm. Words burned into the card:
CASSANDER CALDER
MECHANICAL AFFINITY: UNLOCK
SINGULARITY CORE: SEEDING… 1 %
00:05:00.
The train lurched, not forward but sideways, folding the street like paper. The conductor stepped aside. Cass leapt the gap as the pavement behind him flattened into two dimensions and vanished. He landed inside Car 6— a workshop bathed in red safelights, walls lined with tools that hadn't been invented yet.
The doors sealed. Acceleration pressed him to the floor. Through a porthole he watched London invert, crumble, and finally unwrite itself— a city-sized eraser smudge shrinking to a point of perfect black.
The intercom crackled.
> "Welcome aboard the Obsidian Express. Next departure in ninety days. Please ensure your concept of self is securely stowed."
Cass looked at the ticket again. The percentage ticked upward: 3 % … 4 % …
His reflection in a chrome panel stared back— but the eyes were already a shade paler, as if some pigment had been siphoned away.
He pressed the stopwatch.
00:00:00.
A new timer lit up on the ceiling in glowing white digits:
DAY 90 – 23:59:57… 23:59:56…
The train screamed into the dark, and Cass Calder realized two things with crystalline certainty:
1. He was the only engineer left who could keep the engine running.
2. The fare was time itself— and the meter was already ticking.