The city had grown quieter, smoother, almost too orderly. Lanterns traced predictable arcs along the streets. Patrols moved with synchronized precision. Supplies arrived on schedule. Emergencies were triaged with clinical efficiency. And yet, beneath that surface of calm, something trembled.

It began in the eastern quarter.

A fire had broken out in one of the older tenement blocks—a tangled cluster of wooden rooftops and narrow alleys that defied easy access. Smoke curled against the ...