It was a dawn of sorts, but it was bony and stark, with none of the richness and fleeing colours of an Earth-orbit sunrise. This was an airless world with no atmosphere to refract sunlight, to bend it up from below the horizon, and create a pre-dawn glow in the sky. So sunrise was instantaneous: one moment it was night, the next a line of fire had straddled the horizon, poking through the mountains and crater rims there.

The light fled across the bare surface, casting shadows hundreds of miles long from mountains and broken crater walls. The smaller, younger craters were just wells of darkness in the flat light. For the first time, the Moon looked jagged and exotic, a craggy, romantic alien world; but he knew it was only an artifact of the light, giving the old, eroded Moon a rugged grandeur it didn’t merit—

The engines lit.

For a couple of weeks the rig workers had noticed strange happenings.

The sea water here in the North Channel, not far from the mouth of the Clyde, was sometimes so warm it steamed. And there was that prevailing stink of rotten eggs. Hydrogen sulphide, the lab boys said.

William Calder didn’t think much of it. Aged twenty-seven, with a wife, Jenny, and two kiddies in a tenement block in the Gorbals back in Glasgow, he’d always known the work on this exploratory oil rig was going to be hard and dirty and dangerous, even before Scotland started bloody blowing up. Twelve hours on, twelve hours off, weeks or months away from home; William just kept himself to himself and got through his work, like serving a sentence, which, if truth be known, William had done once or twice in his younger days.

But now it was nearly the end of his tour of duty — nearly the end for everybody, as the rig was going to be evacuated in a few days because of the volcano stuff — and William would be going home with his bank account stuffed with money, more than enough to get his young family out of Glasgow for good, and into some safe bolt hole in England, as far south as they could bloody go without falling into the English Channel.

So he was sitting with a six-pack in the cinema, watching Independence Day for the fourth time, when the first explosion came.

The rig shuddered, and there was a wail like a scream.

“Jesus Christ, that’s a gas leak,” said Jackie Brown, one of the blasting foremen.

Everybody stood up.

The film jammed, and burned through with shocking suddenness, a black circle just gushing outwards across the screen.

Then the plastic walls of the room started to melt, and the workers, men and women alike, started to run.

In the corridor outside, William saw people grabbing at metal railings. There was a sound of sizzling, like bacon, and people screamed. The railings were too hot to touch.