The flip-letters click over on Tannoy’s Miniaturized Steam-Driven Diary. IT EVEN, they read, TAKES DICTATION STOP GRITTY AMAZING STOP

Maclemond glances back at the pressure-car behind them: at the two men of indeterminate race pumping bellows, the third shoveling fuel, all inked with thick blue-black coal smoke. The roaring furnace drives the turbine, which in turn spits and crackles blue where it meets the two little rubber-sleeved leads that trail up to the diary’s back socket.

“Have you considered,” says Maclemond carefully, “using a pocket notebook?”

Tannoy blinks. “Do they make one with games on it?”