He stretched the motion field outward and found more viewers nested like dolls. Shadows that had once been anonymous were now linked to other households — a woman across the alley pausing to tie a shoelace, a courier's shoulder tilting the same way as the man’s had. Motion signatures matched; the viewerframe suggested: Shared trajectories detected. Kai felt a cold thing in his chest: the red coat's path wasn’t unique. It threaded through a crowd of small, ordinary convergences. Was it memory or contagion?