THREE

      ‘There it is, then,’ said Swanson. ‘That’s the Barrier.’

      The Dolphin, heading due north, her great cylindrical bulk at one moment completely submerged, the next showing clear as she rolled heavily through the steep quartering seas, was making less than three knots through the water, the great nuclear-powered engines providing just enough thrust to the big twin eight-foot propellers to provide steerage way and no more: thirty feet below where we stood on the bridge the finest sonar equipment in the world was ceaselessly probing the waters all around us but even so Swanson was taking no chances on the effects of collision with a drifting ice-block. The noonday Arctic sky was so overcast that the light was no better than that of late dusk. The bridge thermometer showed the sea temperature as 28° F., the air temperature as –16° F. The gale-force wind from the north-east was snatching the tops off the rolling steel-grey waves and subjecting the steep-walled sides of the great conning-tower – sail, the crew called it – to the ceaseless battering of a bullet-driven spray that turned to solid ice even as it struck. The cold was intense.

      Shivering uncontrollably, wrapped in heavy duffel-coat and oilskins and huddled against the illusory shelter of the canvas wind-dodger, I followed the line of Swanson’s pointing arm: even above the high thin shrill whine of the wind and the drum-fire of the flying spray against the sail, I could hear the violent chattering of his teeth. Less than two miles away a long, thin, greyish-white line, at that distance apparently smooth and regular, seemed to stretch the entire width of the northern horizon. I’d seen it before and it wasn’t much to look at but it was a sight a man never got used to, not because of itself but because of what it represented, the beginning of the polar ice-cap that covered the top of the world, at this time of year a solid compacted mass of ice that stretched clear from where we lay right across to Alaska on the other side of the world. And we had to go under that mass. We had to go under it to find men hundreds of miles away, men who might be already dying, men who might be already dead. Who probably were dead. Men, dying or dead, whom we had to seek out by guess and by God in that great wasteland of ice stretching out endlessly before us, for we did not know where they were.

      The relayed radio message we had received just forty-nine hours previously had been the last. Since then, there had been only silence. The trawler Morning Star had been sending almost continuously in the intervening two days, trying to raise Drift Station Zebra, but out of that bleak desert of ice to the north had come nothing but silence. No word, no signal, no faintest whisper of sound had come out of that desolation.

      Eighteen hours previously the Russian atomic-engined Dvina had reached the Barrier and had started on an all-out and desperate attempt to smash its way into the heart of the ice-cap. In this early stage of winter the ice was neither so thick nor so compacted as it would be at the time of its maximum density, in March, and the very heavily armoured and powerfully engined Dvina was reputed to be able to break through ice up to a thickness of eighteen feet: given fair conditions, the Dvina was widely believed to be capable of battering its way to the North Pole. But the conditions of the rafted ice had proved abnormal to a degree and the attempt a hopeless one. The Dvina had managed to crash its way over forty miles into the ice-cap before being permanently stopped by a thick wall of rafted ice over twenty feet in height and probably more than a hundred deep. The Dvina, according to reports, had sustained heavy damage to its bows and was still in the process of extricating itself, with the greatest difficulty, from the pack. A very gallant effort that had achieved nothing except an improvement in East-West relations to an extent undreamed of for many years.

      Nor had the Russian efforts stopped there. Both they and the Americans had made several flights over the area with front-line long-range bombers. Through the deep overcast and driving ice- and snow-filled winds those planes had criss-crossed the suspected area a hundred times, searching with their fantastically accurate radar. But not one single radar sighting had been reported. Various reasons had been put forward to explain the failure, especially the failure of the Strategic Air Command’s B52 bomber whose radar was known to be easily capable of picking out a hut against contrasting background from ten thousand feet and in pitch darkness. It had been suggested that the huts were no longer there: that the radar’s eye was unable to distinguish between an ice-sheathed hut and the thousands of ice-hummocks which dot the polar cap in winter; and that they had been searching in the wrong area in the first place. The most probable explanation was that the radar waves had been blurred and deflated by the dense clouds of ice-spicules blowing over the area. Whatever the reason, Drift Ice Station Zebra remained as silent as if no life had ever been there, as lost as if it had never existed.

      ‘There’s no percentage in staying up here and getting frozen to death.’ Commander Swanson’s voice was a half-shout, it had to be to make him heard. ‘If we’re going under that ice, we might as well go now.’ He turned his back to the wind and stared out to the west where a big broad-beamed trawler was rolling heavily and sluggishly in the seas less than a quarter of a mile away. The Morning Star, which had closed right up to the edge of the ice-pack over the last two days, listening, waiting, and all in vain, was about to return to Hull: her