You might wonder what a man who managed to survive alone on a desolate world for more than a decade might have to learn in terms of survival skills. But everything I had done to keep myself alive during those long, hard years had been learned through trial and error – with the emphasis on error. In my desperation to find more of the antidote Red Harvest had developed, and which kept me alive, I had taken such enormous risks that it pained me to remember them. The fact that I had survived at all had been as much down to luck as anything else.

My last week of training following Casey Vishnevsky’s apocalyptic brand of show-and-tell, however, had more to do with logistics and operational procedures. I learned how to program a transfer stage control rig to get me back to the island in an emergency. I learned more about the ‘null sequences’ Nadia had warned me of, and how very dangerous inputting one could be. They showed me how to operate the specialized walkie-talkies used by the Pathfinders, and how to set up an impromptu communications network in case the main one failed. Finally I learned about the automated reconnaissance drones they used, and how they could be controlled through a computer built into the control rig itself. They could also be operated from remote machines that were essentially rugged laptops. There was more than enough to keep me too tired and worn out to do anything remotely resembling socializing, let alone have the leisure to wonder about that whole bizarre encounter with Chloe.

I had other things on my mind too. Earlier that week, while grabbing something to eat at the Hotel du Mauna Loa, I had learned from Nadia just how the whole Pathfinder project came into existence.

‘Casey Vishnevsky was the first of us they retrieved,’ she had explained over a bowl of broth, a bottle of beer by her side. ‘They didn’t go looking for him. They just found him, while they were exploring his alternate.’

‘And he was the last man alive there?’

She chuckled and took a sip of her beer. ‘Who knows? Maybe there were other people out there, but they didn’t happen to find them. Are you certain there was no one left alive anywhere on your alternate?’

‘No, of course not. There might have been, but . . .’