He sees fluid swaying in a semicircle and his balance is the bubble in a spirit level. Anvil, oval window, stirrup - cityscape of minute parts - he doesn't want to know. Choosing the Tube map he journeys, connects, anticipates snafus: the lungs of the Northern line, cradling the ruddy pump of Holborn, as clean and clear as Metropolitan nostrils. The right foot of Heathrow Terminals shoots scores of planes a day. Slowly, steadily, he teases Operation from the pile of childhood games.