By midnight on the twenty-first day, the comms protocol for the three-point shutdown had been engineered with triple redundancy, ensuring that no single broken wire, dead battery, or burst pipe could blind the crews.
The main network was the clockwork tracking data feed sent across the Courtesy Bridge from Imran’s console in Harrowby, providing real-time pressure readouts, heat curves, and timed together countdown timers on the brass message slates mounted at each station.
The backup network was Hal Rook’s clockwork pull-cable system. A three-eighths-inch glowing-bronze wire strung through lead channel along the gallery walls, connected to heavy brass warning bells at each station. A single pull on the wire tolled all three bells at the same time. Three rapid pulls triggered the master stop-work alarm.
The tertiary network was the human runner line through Imran’s lantern beetle gallery. Young Tavi and two swift-footed apprentices from the boat ramp were assigned as dedicated messengers, equipped with oilcloth pouches, grease-pencils, and rubber-soled clogs, ready to sprint the cool passage if both clockwork and space-folding signals failed.
‘Three lines of defense,’ Korr Var pronounced, testing the tension on the bronze pull-wire with his thumb. ‘If the magic slate fails, the bell wire holds. If the bell wire snaps, the boy runs. Hal Rook always said that a bridge without three ways to send a message is just a scaffold waiting for an undertaker.’
