"I'll leave you to it, then. I'll get the searchlight." I made off towards the mound of snow that loomed high to the westward of the cabin, broke step and listened. There was no sound to be heard, nothing but the low-pitched moan of the wind on the ice-cap, the eternal rattling of the anemometer cups. I turned back to Jackstraw, my face bent against the knifing wind.

"The plane – have you heard the plane, Jackstraw? I can't hear a thing."

Jackstraw straightened, pulled off his parka hood and stood still, hands cupped to his ears. Then he shook his head briefly and replaced the hood.

"My God!" I looked at him. "Maybe they've crashed already."

Again the shake of the head.

"Why not?" I demanded. "On a night like this you wouldn't hear a thing if they crashed half a mile downwind."

"I'd have felt it, Dr Mason."

I nodded slowly, said nothing. He was right, of course. The frozen surface of this frozen land transmitted vibration like a tuning-fork. Last July, seventy miles inland, we had distinctly felt the vibration of the ice-cap as an iceberg had broken off from a glacier in a hanging valley and toppled into the fjord below. Maybe the pilot had lost his bearings, maybe he was flying in ever-widening circles trying to pick up our lights again, but at least there was hope yet.

I hurried across to where the tractor, sheeted in tarpaulin, lay close in to the high snow wall that had been cut down the middle of the drift. It took me a couple of minutes to clear away the accumulated snow at one end and wriggle in under the tarpaulin. There was no question of trying to lift it – its impregnated oils had frozen solid and it would have cracked and torn under any pressure.

The searchlight, fixed to a couple of bolts on the tractor bonnet, was held down by two quick-release butterfly nuts. In these latitudes, quick-release was a misnomer: the nuts invariably froze after even the briefest exposure. The accepted practice was to remove one's gloves and close mittened hands round the nuts until body heat warmed and expanded them enough to permit unscrewing. But there was no time for that tonight: I tapped the bolts with a spanner from the tool box and the steel pins, made brittle by the intense cold, sheared as if made from the cheapest cast iron.

I crawled out at the foot of the tarpaulin, searchlight clutched under one arm, and as soon as I straightened I heard it again – the roar of aero engines, closing rapidly. They sounded very near, very low, but I wasted no time trying to locate the plane. Head lowered against the wind and the needle-sharp lances of the flying ice, I felt rather than saw my way back to the cabin hatch and was brought up short by Jackstraw's steadying hand. He and Joss were busy loading equipment aboard the sledge and lashing it down, and as I stooped to help them something above my head fizzled and spluttered into a blinding white .re that threw everything into a harsh black and white relief of frozen snow and impenetrable shadow. Joss, remembering what I had completely forgotten – that dousing our cabin lights would have robbed the pilot of his beacon – had ignited a magnesium flare in the slats of the instrument shelter.

We all turned as the plane came into our vision again, to the south, and it was at once apparent why we had lost all sight and sound of it. The pilot must have made a figure of eight turn out in the darkness, had reversed his approach circle, and was flying from east to west less than two hundred feet up, undercarriage still retracted, it passed within a couple of hundred yards of us like some monstrous bird. Both headlights were now dipped, the twin beams a glitter of kaleidoscopic light in the ice-filled darkness of the sky, the twin oval pools of light interlocking now and very bright, racing neck and neck across the snow. And then these pools, increasing as rapidly in size as they diminished in strength, slipped away to the left as the plane banked sharply to the right and came curving round clockwise to the north. I knew now what the pilot was intending and my hands clenched helplessly inside mittens and gloves. But there was nothing I could do about this.

"The antenna!" I shouted. "Follow out the line of the antenna." I stooped and gave the sledge its initial shove as Jackstraw shouted at Balto. Joss was by my side, head close to mine.

"What's happening? Why are we – "

"He's coming down this time. I'm sure of it. To the north."

"The north?" Not even the snow-mask could hide the horror in his voice. "He'll kill himself. He'll kill all of them. The hummocks – "

"I know." The land to the north-east was broken and uneven, the ice raised up by some quirk of nature into a series of tiny hillocks, ten, twenty feet high, tiny but the only ones within a hundred miles. "But he's going to do it, all the same. A belly landing with the wheels up. That's why he reversed his circle. He wants to land upwind to give himself the minimum stalling ground speed."

"He could land to the south, into the wind." Joss sounded almost desperate. "It's a billiard table there."

"He could, but he won't." I had to shout the words to make myself heard above the wind. "He's nobody's fool. He knows if he lands to windward of us, even a hundred yards to windward, the chances of finding our lights, our cabin, in this weather just don't exist. He's got to land upwind. He's just got to."

There was a long silence as we staggered forward, head and shoulders bent almost to waist ievel against the wind and ice-filled drift, then Joss moved close again.

"Maybe he'll see the hummocks in time. Maybe he can – "

"He'll never see them," I said flatly. "Flying into this stuff he can't possibly see a hundred yards in front of him."

The radio antenna, rime-coated now to almost fifty times its normal size, sagging deeply and swaying pendulum-like in the wind between each pair of fourteen-foot poles that supported it, stretched away almost 250 feet to the north. We were following the line of this, groping our way blindly from pole to pole and almost at the end of the line, when the roar of the aircraft engines, for the last few seconds no more than a subdued murmur in the night as the wind carried the sound from us, suddenly swelled and increased to a deafening crescendo as I shouted a warning to the others and flung myself flat on the ground: the huge dark shape of the airliner swept directly over us even as I fell. I would have sworn, at the time, that I could have reached out and touched it with my hand, but it must have cleared us by at least ten feet – the antenna poles, we later discovered, were undamaged.

Like a fool, I immediately leapt to my feet to try to get a bearing on the vanishing plane and was literally blown head over heels by the tremendous slipstream from the four great propellers, slid helplessly across the frozen crust of the snow and fetched up on my back almost twenty feet from where I had been standing. Cursing, bruised and not a little dazed, I got to my feet again, started off in the direction where I could hear the dogs barking and howling in a paroxysm of fear and excitement, then stopped abruptly and stood quite still. The engines had died, all four of them had died in an instant, and that could mean only one thing: the airliner was about to touch down. Even with the realisation a jarring vibration, of a power and intensity far beyond anything I had expected, reached my feet through the frozen crust of the ice-cap. No ordinary touchdown that, I knew, not even for a belly landing: the pilot must have overestimated his height and set his ship down with force enough to crumple the fuselage, to wreck the plane on the spot.

But he hadn't. I was prone to the frozen snow again, ear pressed hard against it, and I could half hear, half feel, a kind of hissing tremor which could only have come from the fuselage, no doubt already splintered and ripped, sliding over the ice, gouging a furrowed path through it. How long this sound continued, I couldn't be sure – six seconds, perhaps eight. And then, all at once, came another earth tremor, severer by far than the first, and I heard clearly, even above the gale, the sudden sharp sound of the crash, the grinding tearing scream of metal being twisted and tortured out of shape. And then, abruptly, silence – a silence deep and still and ominous, and the sound of the wind in the darkness was no sound at all.