Petrovitch pulled out his cash card and held it up.

“You pay next time, Petrovitch.” He shrugged and almost smiled. The lines around his eyes crinkled.

“Yeah, whatever.” He put the card back in his bag. It had only a few euros on it now, anyway. “Thanks, Wong.”

Back out onto the street and the roar of noise. The leaden sky squeezed out a drizzle and speckled the lenses in Petrovitch’s glasses so that he started to see the world like a fly would.

He’d take the tube. It’d be hot, dirty, smelly, crowded: at least it would be dry. He turned his collar up and started down the road toward Clapham South.

The shock of the new had barely reached the Underground. The tiled walls were twentieth-century curdled cream and bottle green, the tunnels they lined unchanged since they’d been hollowed out two centuries earlier, the fans that ineffectually stirred the air on the platforms were ancient with age.

There was the security screen, though: the long arched passage of shiny white plastic, manned by armed paycops and monitored by gray-covered watchers.

Petrovitch’s travelcard talked to the turnstile as he waited in line to pass. It flashed a green light, clicked and he pushed through. Then came the screen which saw everything, saw through everything, measured it and resolved it into three dimensions, running the images it gained against a database of offensive weapons and banned technology.

After the enforced single file, it was abruptly back to being shoulder to shoulder. Down the escalator, groaning and creaking, getting hotter and more airless as it descended. Closer to the center of the Earth.

He popped like a cork onto the northbound platform, and glanced up to the display barely visible over the heads of the other passengers. A full quarter of the elements were faulty, making the scrolling writing appear either coded or mystical. But he’d had practice. There was a train in three minutes.

Whether or not there was room for anyone to get on was a different matter, but that possibility was one of the few advantages in living out along the far reaches of the line. He knew of people he worked with who walked away from the center of the city in order to travel back.

It became impossible even to move. He waited more or less patiently, and kept a tight hold of his bag.

To his left, a tall man, air bottle strapped to his Savile Row suit and soft mask misting with each breath. To his right, a Japanese woman, patriotically displaying Hello Kitty and the Rising Sun, hollow-eyed with loss.

The train, rattling and howling, preceded by a blast of foulness almost tangible, hurtled out from the tunnel mouth. If there hadn’t been barriers along the edge of the platform, the track would have been choked with mangled corpses. As it was, there was a collective strain, an audible tightening of muscle and sinew.