The Enginewright's Oath

Beneath the city’s braided arteries of steam and copper, Ada Corvin tightened a brass collar until it sang. The Underworks smelled of hot oil and coal, of metal warmed to patience and then coaxed into obedience. Around her, pipes threaded like veins through the ribcage of Ironwold, carrying pressurized breath that lifted platforms, fed the great kitchens, and turned the endless face of the Hearthwheel—the ancient regulator that set the city’s tempo. It was a machine as old as the statutes that kept the Conclave in custody of power, a monstrous clock whose spokes held neighborhoods in time.

Ada’s fingers moved with the steady, practiced rhythm of an enginewright who had learned to read temper and fatigue the way some people read faces. Where flesh had been, a careful arrangement of gears and stamped plates finished in dull nickel answered. Her prosthetic hand, the one she had fabricated and taught to obey, fitted around a piston rod with the intimacy of remembrance. She had made that hand while Juniper Hale had laughed in the doorway, calling her “half contraption, half conscience,” and she remembered the way his eyes lingered on the notes pinned to his bench—schematics that smelled faintly of tobacco and hope.

The night’s repairs were small: a gated valve, a misaligned governor on an auxiliary pump that fed the communal laundries of a tenement. Neighbors aboveground would wake to water and warmth because Ada had stayed late to listen to the pipes. For a long moment she allowed herself one small satisfaction—the quiet kind that belongs to lovers of machines. Then the bell at the workshop thudded in the way a city announces the unwelcome: a seeking, officious ring.

Juniper’s workshop was more a parish than a shop. People came there with problems they could not explain away with coins—difficulties of breath, of thirst, of lifts that never came. Tonight, a knot of mourners had already gathered; the old inventor’s bench was draped and the scent of boiled coffee shaded the room. Hale’s passing had been sudden, the kind of absence that leaves instruments tuned to wrong notes. Ada felt the hollow well of grief, the brittle ache she learned not to speak of in the presence of the Conclave’s men.

When the inspectors arrived, they wore formal faceplates polished to reflect guild badges and civic seals. Their coats were stitched with the Conclave’s sigil, an oblong gear enclosing a balancing hand. They moved with a deliberation meant to convince the submissive that submission was inevitable. Ada folded herself into the shadow of the workbench and pretended to file a strip of metal while they cataloged boxes of Hale’s possessions and took measurements of apparatus with tools that clicked in precise, clinical ways. A tall man with a monocle—his breath smelled faintly of peppermint and law—asked questions about recent experiments. Ada answered as if she were a clerk instead of a maker, because answers might protect a workshop but silence could save a life.

The bequest arrived like a small, heavy argument: a wooden case with brass bands, sealed with Juniper’s personal cipher beneath a lock that hummed when Ada held the prosthetic to it. The device inside was wrapped in oilcloth and smelled faintly of coal and spent solvents. Hale had pressed a small envelope into her hand before he died, words scrawled in a hand that had once taught her to steady a lathe: Keep this. For the city, not for the Conclave. For hands you can trust. Ada did not yet understand what she had been entrusted with, only that the inspector’s gloved fingers had already brushed the case and that eyes moved over it like vultures measuring weight.