Ash filtered down through fissures in the vaulted ceiling, dusting the broad shoulders of Dravis Granger like gray snow. He ignored it. The tremor rolling under the aqueduct floor mattered more than the debris drifting from above. A deep-set vibration beat its way through stone and sinew, landing in his boots as an arrhythmic metronome—two steady pulses, one softer echo, a pause. He matched his respiration to that cadence, lungs rising on the first thrum, falling on the second, holding on the lull. Stability, here, was a timing problem.