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.

The policeman stepped forward. His blue trousers and yellow jacket were stained green where he’d been thrown into the grass. “Who else? It isn’t too late yet. I’ll do all I can to get you down from here in safety.”

There was a stir among the cultists, and a stir in Mike’s heart. Not too late. Could that be true?

People were getting up around him, brushing off scuffed and torn suits. Sheepishly joining the copper.

But it is too late, Mike thought. It had been too late for them all, for the whole city maybe, from the moment he had brought those Moon dust grains to this place.

He had let Henry down, betrayed a trust. He had killed the city, even his family, and he deserved to suffer.

…Or maybe, as Bran expressed it, all he had done was to open the door, the hatch to the Airlock that was waiting for them all. And in that case, he deserved the peace and joy and endless light that would follow.

So he ignored the people losing their faith, scurrying down the rock after that copper like frightened rabbits. Perhaps there was nobody left but himself and Bran, but that was okay too. There would be room for them all later. Room for a planet-ful of lost souls.

He looked for Bran. But Bran had gone.

That was puzzling. But even that didn’t seem to matter.

“One hundred feet… eighty feet… eighty feet.”

“Roger that, eighty feet.”

“Power lines a quarter mile.”

“Roger, power lines. Pulling up.”

The surge upward caught Henry by surprise. His attention had been fixed on the evolution of the Seat; suddenly he was pushed down in his jump seat, his consciousness forced back into his fragile body, hurled around inside this clattering contraption.

“One twenty… one fifty… one eighty… five hundred feet now.”

“Five hundred feet. I have the lines visual. Over we go.”

Henry saw the power lines pass seemingly feet below the Chinook.

“Okay, going lower—”

The Chinook orbited over the south face of the Seat once more.

In the last few seconds, the landsliding had become intense. As Henry looked down, it was as if everything south of a line drawn east-west from the Salisbury Crags to the Dunsapie Loch was beginning to move. The nature of the movement was eerie — like nothing he had seen before — not truly a landslide, for there was no lateral movement; rather, the whole mass was rippling and churning up, basalt shattered and turned to a crude fluid by the immense forces stirring within.

And now, at last, the whole south side of the Seat began to slide southwards along a deep-seated plane. Already outlying billows of dust and ash were reaching Duddingston Loch and Prestonfield, the suburb to the south of the Seat, mercifully evacuated—

That was when the explosion came.

Red-hot stones were hurled yards into the air. They came down hissing on the grass. Ash was hosing out, black outside, red-lit within; a cinder cone was already building up around the aperture.

The ground shuddered. There were more deep-throated cracks and explosions: Mike was hearing the voice of the ground coming apart, new fissures and vents opening up.

Mike repeated one of Bran’s favourite mantras. “Christmas Eve, 1968. In the beginning, God created the Heaven and the Earth…”

He heard people join in. “And the Earth was without form and void, and darkness was upon the face of the deep.” He was not alone, then. “And the spirit of God moved upon the face of the waters—”

The ground shuddered, and he was thrown flat again, his face pressed into the grass. The first stones had become a fount of boulders, incandescent bombs hurled so far into the air they passed out of his sight, into the ash cloud that was gathering above him.

Lightning sparked in the cloud. The sunlight was blocked out. He was enveloped in heat.

Mike was sure there was nothing like this in the literature, this sudden and spectacular opening up. But then, there was nothing in fifty thousand years of human history, nothing in five billion years of Earth, like the Moonseed.

The noise had merged into a roar now, continuous, the shuddering unending. But still he could hear his own voice.

“And God said, ‘Let there be light.’ And there was light.”

The ground split again, gas and steam rushing all around him. He heard a scream, unearthly; he was scorched by the heat, but still, it seemed, uninjured. He could scarcely breathe, the air was so hot and thick with the ash.

The ground subsided under him.

In the darkness, he seemed to be falling. Perhaps he would fall all the way to the centre of the Earth, hollowed out by Moonseed.

But now the ground returned, slamming up under him, and he fell on his back, the soil and grass and rock and heather and moss rubbing against his flesh.

He was rising into the roiling ash cloud. It rose up above him, lightning sparking. Remarkably, he still felt no pain, no real discomfort.

There could be only seconds left, though.

Far above, a glint of metal against a square inch of blue sky. A helicopter?

He tried to shout, but he had no voice.

And God saw the light… That it was good…

But now the ash descended on him — oh, Jesus, it was hot, it was burning — and there was no more light.

The cloud of dust and steam billowed upwards, thrusting like a fist towards the Chinook.

“Get us out of here,” Henry said. “Now.”

The pilot didn’t need telling twice. He opened up his throttle and the Chinook dipped, its big rotors biting into the turbulent air.

Henry looked back. The cloud, a black wall, hundreds of feet high, seemed to be catching them up.

The Chinook lurched; the pilots fought for control.

There was an explosion nearby: a crackle of acoustic shock waves, a blast of light, as if someone was shooting at the chopper.

“What—”

“Hold on!”

The Chinook rocked violently.

“Break left! Break right!”

The Chinook banked; Henry grabbed the frame, but even so he was thrown from side to side.

Thick and viscous magma, he thought. Undisturbed for three hundred million years. Heavy with dissolved gases. Suddenly the Moonseed takes the lid off. The magma tears itself into hot fragments, that jet upward or tear out of the new/old vent. Hurling volcanic bombs into the air, even high enough to threaten this Chinook.

Understanding it, he found, was no reassurance right now.