Inside the lobby, the messenger icons waited on violet-shaded lines pulsing through the floor, leading to the service desk subprocessing unit at the head of the node lobby. White-uniformed control modules slaved to the SPU directing the messenger icons to the chrome-mirrored walls at the left and right of the lobby. The messenger icons moved briskly up the lines, then across the front of the service desk to the sides of the lobby, where they vanished into the mirrored walls.