By the time the first tremor ran along the vault's iron ribs, Nia Kestrel was already down in the lower maintenance galleries, fingertips tracing the fine ridges of harmonic seamwork. The vault smelled of warm oil and cold stone; its breathing was a thing she had learned to read. Tubes murmured, pressure gauges winked in steadier arcs, and a deep, patient hum—almost like a sleeping animal—sat in the chest of the building. For years she had mapped that hum the way others mapped coastline or weather on a chart. She could tell, from a thin change in pitch, whether the northward channel would lean three degrees by evening or if a liftline needed a new brace.
The tremor made a hairline complaint against the hull. It should have been nothing—an eddy in the sky currents, a momentary shift in the floating banks that chased one another above the straits. But the sound that followed was wrong: a clipped, ragged note that didn't belong to any safe cycle. Nia paused, palms cold against a maintenance hatch. A distant bell from the harbour stuttered and then stopped as if someone had grabbed the rope between strikes. Overhead, the sky took on the sickly green of sudden motion.
She could have stayed with the instruments. Protocol called for keeping to stations until commands arrived. Instead she ran. The stairwell was narrow, and the town around the vault felt smaller when storms began to rearrange the world. Outside, the harbour piers that sat like fingers along the water's edge were already slipping out of concord with the moorings—chains whining, bollards straining as islands drifted on currents that did not belong to any map.
Captain Oren Blythe was on the first pier, sleeves rolled and hair matted with spray, shouting orders to a handful of dockhands as if his voice alone could hold stone to place. He looked like a man who had learned the sea by being struck by it enough times to smile through the next impact. Nia felt the grip of guilt as she slipped past him; the old captain had taken her in after the apprenticeship program had eviscerated her confidence, using blunt words and rough tasks to rebuild the parts of her that had snapped. He glanced up, saw her, and his smile vanished—something in his face said he knew this tremor for more than a stray wind.