Example: Mateo, a bicycle courier by day, became a courier of other things at night—messages erased on napkins, three nails threaded on a string, a photograph of a child whose name had been changed in the registry. He pedaled a route that stitched the old quarter to the new, memorizing the shadows where municipal lamps flickered differently, the single loose cobblestone that would throw a cart if hit wrong. His map was mnemonic: a tree with a broken limb = left; the café ashtray with two cigarette butts = right; the laundromat’s humming drum = stop and wait.