Kenning was ahead, his sledge making a hissing sound as he pulled it over the ice, his red arctic wear bright against the white of the snow and the almost unbearable blue of the sky. The mountains reared to our left, the exposed rock predominantly brown in the sunshine, the snow vaulting gracefully upwards in smooth curves. To the right there was nothing – only the ice-shelf, almost flat out to the horizon, like solid light in the punishing glare of the sun.

A mighty wall of rock was exposed; the lowest ice levels in centuries, prompted by the highest temperatures, had melted so much ice that there was more of the bare rock of Antarctica visible than at any previous time in history. The mountain range curved round, only a part of it visible as the two men trudged towards it.  The shadows of seracs and pillars of ice showed black against the brown of the rock in the light of the sun. And there Kenning’s eye caught an anomalous shadow, a shadow bigger than the ice that caused it. It was still distant; John frowned under his goggles. After three weeks he was tired – and patient. Whatever it was could wait until they were closer. More steady footsteps, pulling hard against the heavy harness, straining against the wide straps that connected him to his sledge. His feet crunched against the ice and snow underfoot. His breath rasped in his ears, his heart beat thundering. The path lay slightly uphill, and the two men slowed down as the slope increased. As the incline leveled off again, Kenning stopped and leaned heavily on his sticks. He glanced around at his companion, and then back at the rock wall. The strange shaped shadow was some form of enormous cave entrance or depression, he thought. It was still a good five kilometres distant.

As they drew nearer to the rock wall, drawn automatically by the strange cave exposed by the retreating ice, something quite appalling started to dawn on them. For as their comprehension of the approaching cliff face grew better, they realised that this depression in it was quite artificial.  It appeared to be the entrance to a tunnel, perfectly round in shape, though half buried in ice. It was clearly enormous, the roof perhaps thirty metres above the surface of the ice, and even then the ice filled half of what was a large round shaft bored directly into the mountain.

Phil Keynes stared into the blackness of the tunnel. Ice filled over half of the wide bore, a ribbon of silver and grey disappearing into the gloom, colouring from white into grey as the light faded. He looked up at the sides, taking in the smoothness of the finish, the grey colour of something that looked like concrete contrasting with the light brown of the surrounding rock. This tunnel entrance had lain buried and concealed in the ice for millennia, brought to light only by the changes in climate that had started at the end of the last century. That it was not natural was beyond any shadow of a doubt; it must have been built in dizzying antiquity, perhaps even before the Antarctic ice cap had come into existence. It clearly predated all of human civilisation. Such a structure might be twenty thousand years old – or a hundred million. A very strange and ancient feeling arose deep inside Phil Keynes, not exactly terror, not exactly excitement. Here there was something awesome, maybe something great, perhaps something horrible beyond human comprehension. The stygian gloom of the tunnel as it disappeared into the rock of the mountain seemed to contain every kind of childhood bogeyman that ever existed. The atavistic fear of the dark that lies hidden even in the strongest men arose in Phil. And against himself, a Royal Marine and experienced soldier who had thought he had seen everything, he shivered.