Tobias edges sideways, one careful step at a time, keeping his shoulder blades against the cold stone. The chalk scritches in a slow, steady rhythm — a sound he prays will swallow the scuff of his boot soles. He doesn't look at the figure; eyes on the lantern-lit circle, he tells himself, because looking means flinching, and flinching means noise. Three steps. Four. The chalk stops. He freezes, breath caught in his throat. A long beat passes before the soft humming resumes and the scritching begins again. He lets the breath out. Two more steps and pale morning light is visible, just around the curve of the passage — then his foot finds a loose pebble and it skitters forward with a bright, sharp click that rings off every wall at once. The humming stops.