That wasn’t the worst of it, though. Here, Ted could tell he was close to the Moonseed.

The air was so still. And there was a tinge, a silvery glow, as if the sunlight was being scattered by a smog of iron filings.

At last, the world was reduced to its essentials. Moonscape below, silver-stained sky above, himself and Blue and this rubbly plain, his own breathing, the steady thump of his old heart, the tug of pain at his wounded chest. And as his faceplate grew opaque with the mist of his breath, the fine layer of ash dust he had to keep wiping away, his universe narrowed further, became simpler still.

It was almost peaceful.

He wondered what he would smell, if he raised his hood.

He thought about the Moonseed, and meringues, and the unknown pit of alien forms somewhere beneath his feet. It was as if the Moonseed had turned this place into an alien landscape, not Earth any more.

Blue mounted a thick slab of wall, breathing hard, and looked back at Ted. “You are doing well.”

“Thanks.”

“For a geologist this is not so strange, this landscape.”

“What?”

Blue waved a gloved hand. “No life. Nothing but minerals. The world reduced to its essence, by the burning power of the alien among us. Come, my friend. Not much further.” And he stepped forward and continued his progress.

After a time, the housing remains ran out. They had reached the western edge of Holyrood Park, the old garden which had contained the Seat, overlooked here by the Salisbury Crags.

The Crags had gone. The Moonseed pool had come spilling out from the Crags in great silvery tongues. But the turf survived, in narrow bridges pushing a few yards more into the Moonseed, evidently fragile. Ted could see the burned and fallen trunks of trees, grey and lifeless on the scorched, ash-strewn turf.

Further to the east, towards the heart of the Seat, there was only the silver-grey glow of Moonseed light, all the geology and structure there — a billion years of Earth history — reduced to alien smoothness.

“Come on,” Blue whispered. “We can go a little further.”

Blue stepped forward, onto a wider neck of ground. He tested every step, as if he was walking onto an ice floe. Ted followed a few yards behind, trying to stick to the footsteps Blue had left in the ash. Fixed to his hood Blue had a chest-mounted still camera and a small video camera — the kind they put in cricket stumps, Ted thought irrelevantly. Blue was working the still camera now, and talking patiently into a microphone inside his hood.

After maybe fifty paces Blue stopped.

Ted came to stand beside him. The neck of blackened turf went on some yards further, but Ted could see how cracked and fragile it was becoming.

“Notice how it’s not advancing,” Blue said.

“What?”

“The Moonseed.”

“Why?”