The plug looked extraordinarily ugly from the air, a crude knot of basalt protruding from the ground, old and stubborn, somehow magnificent. Its several ancient vents were easy to make out, the basalt outline clear beneath a thin coating of heather. The Seat had, thought Henry, already seen off three hundred million years of weather, the titanic scraping of the ice, the pinprick depredations of man. But it wasn’t going to be able to see off the Moonseed. And there, indeed, close to the summit, was the central pool, obscured a little by the smoke from the ruin of Abbeyhill, shining like a coin in the ashen light.

And elsewhere, there were signs of magmatic activity: the blur of steam and smoke, perhaps a fissure near the crest of the Seat. He wished he had a cospec up here. A camera, even.

Incredibly, there were people on the Seat: still, even now, with the whole damn city evacuated, right at the heart of the thing.

Then, as the Chinook completed its second orbit of the Seat, Henry thought he spotted landsliding, on the south face, away from the ragged patches of Moonseed.

It was beginning.

He tapped the pilot on the shoulder. “Could you circle a few times? I’d like to take a closer look.”

“Surely, sir. Break my right now. That’s nice…”

The Chinook dipped to the right and hurled itself into a dive.

The copilot intoned, “Seventy feet, ninety knots. Sixty feet, one hundred knots.”

Arthur’s Seat approached, like an obstacle in a Disneyland ride, and the Chinook soared, following the ground’s blunt contours.

The pilot whooped. “Raw sex!”

It came more abruptly than Mike Dundas had expected.

There was an earthquake, a single jarring shift sideways, that sent them all sprawling, even Bran.

Mike sat up. His arm was bruised, but nothing was broken.

The ground shuddered. Aftershocks.

But Bran was sitting up. He looked around the group, locking each of them in turn in eye contact. “Not long now,” he said, his voice thin and clear. “The EVA is almost terminated. All that remains is for the controllers to choreograph our reentry. We must accept, and be prepared.”

Be prepared. Accept. Yes.

A tall, older man broke out of the group with a kind of sob. “Christ, I don’t want to die. Not for a fucking junkie like you.” He ran, stumbling.

Bran just watched him, his calm undisturbed.

The ground cracked. There was a sound like thunder emanating deep from within the earth. Another jolt.

A fissure opened up, stretching back towards the peak of the Seat; it was just a few inches wide, and the earth around crumbled into it. From a hole at one end of the fissure, smoke, steam and bursts of red hot cinders broke into the air.