He jumps up and down agitatedly as he shoves Gregor down the spiral staircase into the shelter, like a short troll in a blue uniform stocking his larder. "Three minutes!" shouts the troll. "Hold fast in three minutes!" So many people in London are wearing uniforms these days, Gregor reflects; it's almost as if they believe that if they play their wartime role properly the ineffable will constrain itself to their expectations of a humanly comprehensible enemy.

A double-bang splits the air above the park and echoes down the stairwell. It'll be RAF or USAF interceptors outbound from the big fighter base near Hanworth. Gregor glances round: A couple of oafish gardeners sit on the wooden benches inside the concrete tunnel of the shelter, and a louche City type in a suit leans against the wall, irritably fiddling with an unlit cigarette and glaring at the NO SMOKING signs. "Bloody nuisance, eh?" he snarls in Gregor's direction.

Gregor composes his face in a thin smile. "I couldn't possibly comment," he says, his Hungarian accent betraying his status as a refugee. (Another sonic boom rattles the urinals, signaling the passage of yet more fighters.) The louche businessman will be his contact, Goldsmith. He glances at the shelter's counter. Its dial is twirling slowly, signaling the marked absence of radon and fallout. Time to make small-talk, verbal primate grooming: "Does it happen often?"

The corporate tough relaxes. He chuckles to himself. He'll have pegged Gregor as a visitor from stranger shores, the new NATO dominions overseas where they settled the latest wave of refugees ejected by the communists. Taking in the copy of The Telegraph and the pattern of stripes on Gregor's tie he'll have realized what else Gregor is to him. "You should know, you took your time getting down here. Do you come here often to visit the front line, eh?"

"I am here in this bunker with you," Gregor shrugs. "There is no front line on a circular surface." He sits down on the bench opposite the businessman gingerly. "Cigarette?"