“No, not any more,” Yves Gaynes said. “This is just about the only vegetation left on the planet, the old green grass of home. It’s tapegrass, kind of a cross between grass and moss, geneered with a root network that’s the toughest, thickest tangle of fronds you’ll ever see. I’ve broken a spade before now, trying to dig through the stuff. It goes down over sixty centimetres. But we’ve got to grow it. Nothing else can stop soil erosion on the same scale. You should see the floods we get after a storm, every crease in the ground turns into a stream. If they’d had this on Mortonridge it would have been a different story, I’ll tell you.”

“Can you eat it?” Genevieve asked.

“No. The people who sequenced it were in too big a rush to produce something that would just do the job to build in refinements like that. They just concentrated on making it incredibly tough, biologically speaking. It can withstand as much ultraviolet as the sun can throw at it, and there’s not a disease which can touch it. So now it’s too late to change. You can’t replace it with a new variety, because it’s everywhere. Half a centimetre of soil is enough to support it. Only rock cliffs defeat it, and we’ve got limpet fungi for them.”

Genevieve puckered her lips up and pressed herself up against the windscreen. “What about animals? Are there any left?”

“Nobody’s really sure. I’ve seen things moving round out there, but not close, so it could just be knots of dead tapegrass blowing about. There’s supposed to be families of rabbits living in big warrens along some of the flood-free valleys. Friends of mine say they’ve seen them, other drivers. I don’t know how, the ultraviolet ought to burn out their eyes out and give them cancer. Maybe there’s some species that developed resistance; they certainly breed fast enough for it to evolve, and they always were tough buggers. Then there’s people say pumas and foxes are still about, feeding on the rabbits. And I’ll bet rats survived outside the domes if anything has.”

“Why do you come out here at all?” Louise asked.

“Maintenance crews do plenty of work on the vac-train tubes. Then there’s the ecology teams, they come out to repair the worst aspects of erosion: replant tapegrass and restore river banks that get washed away, that kind of thing.”

“Why bother?”

“The arcologies are still expanding, even with all the emigration. There’s talk of building two more domes for London this century. And Birmingham and Glasgow are getting crowded again. We’ve got to look after our land, especially the soil; if we didn’t, it would just wash away into the sea and we’d be left with continents that were nothing more than plateaus of rock. This world’s suffered enough damage already, imagine what the oceans would be like if you allowed all that soil to pollute them. It’s only the oceans which keep us alive now. So I suppose it boils down to self-interest, really. At least that means we’ll never stop guarding the land. That’s got to be a good result.”

“You like it out here, don’t you?” Louise asked.

Yves Gaynes gave her a happy smile. “I love it.”

They drove on through the wrecked land, sealed under its precious, protective living cloak. Louise found it almost depressingly barren. The tapegrass, she imagined, was like a vast sheet of sterile packaging, preserving the pristine fields and spinnies which slept below. She longed for something to break its uniformity, some sign of the old foliage bursting out from hibernation and filling the land with colour and variety once more. What she wouldn’t give for the sight of a single cedar standing proud; one sign of resistance offered against this passive surrender to the unnatural elements. Earth with all its miracles and its wealth ought to be able to do better than this.

They drove steadily northwards, rising out of the Thames valley. Yves Gaynes pointed out old towns and villages, the walls of their buildings now nothing more than stiff lumps drowned under tapegrass, names decaying to waypoints loaded into the Trooperbus’s guidance block. The Trooperbus had left the simple mesh road behind a long time ago when Louise went back into the main cabin to heat some sachets for lunch. They were driving directly across the tapegrass now, big wheels crushing it to pulp, leaving two dark green tracks behind them. Outside, the land was becoming progressively more rugged, with deepening valleys, and hills sporting bare rock crowns clawed by talons of grey-green lichen and ochre fungus. Gullies carried silver streams of gently steaming water, while lakes rested in every depression.

“Here we are,” Yves Gaynes sang out, four hours after they left London.

Ivanov Robson squeezed his bulk into the cab behind the sisters, staring ahead with an eagerness to match theirs. A plain geodesic crystal dome rose out of the land, about five miles wide, Louise guessed; its rim contoured around the slopes and vales it straddled. The dome itself was grey, as if it was filled with thick fog.

“What’s it called?” Genevieve asked.

“Agronomy research facility seven,” Yves Gaynes replied, straightfaced.

Genevieve responded with a sharp look, but didn’t challenge him.

A door swung open at the base of the dome to admit the Trooperbus. Once the door closed, a red fungicide spray shot out from all sides to wash away mud and possible spores from the vehicle’s body and wheels. They rolled forward into a small garage, and the hatch popped open.

“Time to meet the boss,” Ivanov Robson said. He led the two girls out into the garage. The air was cooler than inside the Trooperbus and the Westminster Dome, Louise thought. She was wearing only a simple navy-blue dress with short sleeves. Not that it was cold, more like a fresh spring day.

Ivanov beckoned them forwards. Genevieve double clicked her heel, and glided along at his side. There was a small four-seater jeep waiting, with a red and white striped awning and a steering wheel. The first one Louise had seen on this planet. It made her feel more comfortable when Ivanov sat behind it. She and Gen took the rear seats, and they started off.

“I thought you didn’t know this place,” Louise said.

“I don’t. I’m being guided.”

Louise datavised a net processor access request, but got no response. Ivanov drove them into a curving concrete tunnel a couple of hundred yards long, then they were abruptly out in full sunlight. Gen gasped in delight. The agronomy research dome covered a patch of countryside which was the England they knew from history books: green meadows flecked with buttercups and daisies, rambling hawthorn hedges enclosing shaggy paddocks, small woods of ash, pine, and silver birch lying along gentle valleys, giant horse chestnuts and beeches dotted across acres of parkland. Horses were grazing contentedly in the paddocks, while ducks and pink flamingos amused themselves in a lake with a skirt of mauve and white water lilies. In the centre was a sprawling country house that made Cricklade seem gaudy and pretentious in comparison. Three-storey orange brick walls were held together by thick black oak beams in traditional Tudor diagonals, though they were hard to see under the mass of topaz and scarlet climbing roses. Windows of tiny leaded glass diamonds were thrown wide to let the lazy air circulate through the rooms. Stone paths wound through a trim lawn that was surrounded by boarders of neatly pruned shrubs. A line of ancient yews marked the end of the formal garden. There was a tennis court on the other side, with two people swatting a ball between them in an impressively long volley.

The jeep took them along a rough track over the meadows round to the front of the house. They turned in through some wrought iron gates and trundled along a cobbled, mossy drive. Swallows swooped mischievously low over the grass on either side, before arrowing back up to the eaves where their ochre mud nests were hidden. A wooden porch around the front door was completely smothered by honeysuckle; Louise could just see someone waiting amid the shadows underneath.