The holographic image of the Earth grew even larger, until it reached from the ceiling to the floor. Some trick of the technology now made it appear to be floating against starry blackness, obscuring even those people standing on the far side of the projection from me. I wondered if the technology to do all this came from the Authority’s own parallel. Given they had invented the transfer stages, I felt sure they must be capable of any number of technological marvels.

Someone cut the music, and I saw a microphone had appeared in Casey’s hand. He hoisted himself up on top of the bar, standing carefully until the top of his head brushed against the ceiling. He peered to either side of the projection until he could ascertain that he had the full attention of everyone present.

‘You all hear me okay?’ he asked, his voice booming across the bar. A last few stragglers wandered in from the pool as he spoke. ‘All right, people. Now, me and Wallace only had a couple of hours to edit down what I’d estimate is maybe a couple of thousand hours of footage, but if you weren’t there, it should still give you a pretty damn good idea just what we were dealing with on this latest trip.’

I leaned in towards Nadia. ‘That woman I ran into earlier – Chloe. She’s the only one who isn’t here.’

‘I wouldn’t trouble yourself over it,’ she said quietly, then determinedly turned away from me to watch the show.

The image of the Earth began to shrink again, stopping once the moon came into view. It was immediately clear that the moon was a great deal closer to its parent than it should be.

‘Presenting our world-burster,’ said Casey. ‘What you’re about to see, ladies and gentlemen, would have made generations of action-movie directors cream themselves.’

I had an unsettling realization that we were literally about to see the end of the world – or a world, at any rate. I had initially assumed that Wallace had used some software trick to make the moon and Earth appear to be so close to each other, but I now understood that what I was seeing was real, and it sent a dreadful chill through me.

Screeds of technical data appeared, floating in the air. None of it meant anything to me. Casey handed his microphone down to Wallace, who then began to describe in some considerable detail just how he had yanked data from a network of military satellites in order to gain most of the footage we were now watching.

‘We’re still working on the question of just how this particular extinction event came about,’ said Wallace, ‘but the most likely culprit is a high-energy physics experiment attempting to generate artificial gravitational waves. On a technical note, I—’