The Residue Won't Wash Amber dust clung to the resonance lens where Morri pressed it against the foundation stone, a fine particulate haze that caught the morning light and held it. She wiped the glass with a cloth from her belt pouch, checked the focal alignment, and pressed it back. The reading came through clean: 3.7 thaumic units per cubic metre, consistent with the site's decay profile over the past eleven weeks. She recorded the number in her field notebook without looking up, the pencil finding the correct column by muscle memory alone. The chalk on her left hand was amber. Standard saturated substrate. She had checked it twice since arriving at the site, which was once more than protocol required and once more than she had ever needed before. Site fourteen occupied a narrow strip of collapsed residential terrace along the Reach's eastern margin, where the contamination had eaten through the original ward-stone and left the remaining structures listing at angles that made doorframes into parallelograms. Morri worked the foundation line from north to south, pausing every three metres to take a lens reading and log it. The numbers told a story she had been reading for years — saturation depth decreasing at a rate of point-two units per quarter, drift patterns consistent with a single-source contamination event radiating outward along the substrate's natural fracture lines. She had written variations of this story at forty-seven sites across the Reach. The grammar was always the same: contamination as natural language, decay as a sentence that wrote itself. She logged the fourth reading and moved to the fifth position. The lens showed 3.5 thaumic units. She wrote it down. Under her equipment case, tucked between the padded compartment that held her spare lenses and the reinforced sleeve for the chalk…