Extinction Game by Gary Gibson

These people had kidnapped me, locked
me up, shot me with darts, taken me on a roller-coaster ride to places I hadn’t even imagined might exist, then asked me to work for an organization that revealed nothing about itself, in
return for being rescued. There were plenty of things that didn’t quite add up, and I could sense there was a lot they still hadn’t told me.
    Yet, despite all that, I was desperate to accept what they were offering, regardless of any conditions stated or as yet unstated, because of one single undeniable, irrefutable truth. What they
were offering me was infinitely preferable to what I’d had before. I could see in their eyes that they knew this, and that they knew I knew it. It didn’t matter, and I didn’t
care.
    ‘Then I’ll say yes,’ I replied. ‘Assuming somebody around here can tell me exactly what the hell it is you want me to do.’

FOUR
    Barely a month later, and a few short hours before I found myself trapped in a subterranean cavern, in imminent danger of being swallowed up in a lake of fire, I found myself
standing on the edge of a vast precipice.
    Nadia was with me. At our feet, an enormous shaft at least a mile across had been dug deep into the Icelandic coast. The only light came from the stars above, and from Hekla, a volcano seventy
miles distant that was undergoing one of its periodic eruptions. Its summit burned red, the fiery glow clearly visible on the horizon.
    I was on yet another post-apocalyptic alternate. I had, as yet, seen no other kind of parallel, and yet I knew that by its very nature the multiverse must contain an enormous variety of
timelines where there had been no extinction event within living memory. The Authority’s peculiar obsession with dying or dead worlds was something for which I still had no explanation.
    Integrated circuitry in the visor of my spacesuit compensated for the lack of light, so that I could see where a road had been cut into the walls of the shaft. It spiralled down until it finally
vanished into stygian depths, where not even my suit’s circuitry could compensate. On the far side of the shaft lay the war-ravaged ruins of Reykjavik, where the Icelanders had made their
last stand against invading European and American forces.
    According to the readout on my helmet’s display, it was a chilly 268 degrees below zero, cold enough that the snow lying all around us was composed not of crystallized water, but of frozen
air. As their world spiralled out of its former orbit, moving farther and farther away from the life-giving sun, the atmosphere had grown sufficiently cold that it had frozen into a thin layer
clinging to the ground. Beyond my visor lay only hard vacuum, and certain death were I to remove my helmet.
    Without an atmosphere to scatter the light and make them twinkle, the stars were bright and unblinking. Nadia had earlier, for my benefit, pointed towards the horizon and indicated the rough
location of the sun. I saw nothing except a star a little brighter than the rest, surrounded by unending darkness.
    ‘What is that?’ I asked, seeing a dot of red light flash in one corner of my visor. A faint beeping accompanied it. The air inside the suit tasted dry and rubbery, and my throat
rasped every time I swallowed. There were other readouts, projected onto the interior curve of my spacesuit’s helmet, many of them as yet indecipherable to me. Part of the reason we had come
to this alternate was so I could learn how to manoeuvre inside such suits as this.
    ‘Some kind of alert,’ said Nadia, her voice clipped. ‘I just hope it’s nothing to do with that tremor a minute ago.’
    As it would soon turn out, it had everything to do with the tremor. As if in response, the ground shifted once again beneath our feet, just very slightly, and I automatically stepped back from
the edge of the chasm.
    I looked over at Nadia; her face was barely visible behind the visor of her spacesuit. My suit’s electronics painted