Back in the tractor cabin curiosity had reached fever pitch, but at least three minutes elapsed – three excruciatingly uncomfortable minutes while Jackstraw and I waited for the blood to come surging back through our frozen veins – before anyone ventured to speak. The inevitable question came from the Senator – a now very much chastened Senator who had lost much of his choler and all of his colour, with the heavy jowls, hanging more loosely than ever, showing unhealthily pale through the grey grizzle of beard. The very fact that he spoke showed, I suppose, that he didn't regard himself as being heavily under suspicion. He was right enough in that.

"Made contact with your friends, Dr Mason, eh? The field party, I mean." His voice was hesitant, unsure.

"Yes," I nodded. "Joss – Mr London – got the set working after almost thirty hours' non-stop work. He raised Captain Hillcrest -he's in charge of the field party – and managed to establish a relay contact between us." I'd never heard of the phrase 'relay contact' in my life, but it sounded scientific enough. "He's packing up immediately, and coming after us."

"Is that good?" the Senator asked hopefully. "I mean, how long-?"

"Only a gesture, I'm afraid," I interrupted. "He's at least 258 miles away. His tractor's not a great deal faster than ours." It was, in fact, almost three times as fast. "Five or six days, at the least."

Brewster nodded heavily and said no more. He looked disappointed, but he looked as if he believed me. I wondered which of them didn't believe me, which of them knew I was lying because they knew that they had so thoroughly destroyed all the spare condensers and valves that it would have been quite impossible for Joss to repair the RCA.

The long bitter day, a day filled by nothing except that dreadful cold, an endless suffering and the nerve-destroying thunderous roar and vibration of that big engine, crawled by like a dying man. About two-thirty in the afternoon, as the last glow of the noon-light faded and the stars began to stand clear in the cold and brittle sky, the temperature reached its nadir – a frightening 73 degrees below zero. Then it was, that strange things happened: flashlights brought from under a parka died out inside a minute: rubber became hard as wood and cracked and fractured like wood: breath was an opaque white cloud that shrouded the heads of every person who ventured outside the tractor body: the ice-cap froze to such an unprecedented degree of hardness that the tractor treads spun and slipped on flat surfaces, the crimp marks no more than half-seen hairlines on the ground: the dogs, who could with impunity stand up to howling blizzards that would kill any man, whined and wailed in their utter misery in that appalling cold: and, now and again, like some far-off intimation of doom and the end of the world, a dull rumbling sound would come echoing across the ice-cap and the ground shake beneath the treads of the tractor as some great areas of snow and ice contracted still farther under the iron hand of that glacial cold.

It was then, inevitably, that the tractor started to give trouble: it was only a matter for wonder that it hadn't broken down long before that. What I feared above all was the shearing of some moving metal part, made brittle by that intense cold, that would have been the end of us: a valve-stem, a cam-rod, any one part of the delicate timing mechanism, even so small a thing as a crankshaft pin: it needed just one of these to go, and we would be gone also.

We were spared these lethal mishaps, but what we had was almost as bad. Carburettor ice was a constant problem. The steering box froze up and had to be thawed out by blow-torches. Generator brushes stuck and broke, but fortunately we carried spares enough of these. But the biggest trouble was the radiator. Despite the fact that we had it heavily lagged, the cold penetrated the lagging as if it were tissue paper and the subsequent metal contraction produced distortion. Soon it began to leak, and by three o'clock in the afternoon we were losing water at dismaying speed. I doled out some of our precious reserves of heat pads for Mahler's feet, with the instructions that the water from the snow-buckets on the stove was to be kept solely for the radiator. But even with blow-torches assisting the heat of a stove, the melting of super-chilled snow is a discouragingly slow process: soon we were reduced to pouring half-melted slush down the radiator cap, and finally to cramming snow itself down in order to keep going at all. All this was bad enough: but the frightening thing was that for every pint of radiator liquid lost and every pint of snow-water used to replace it, the anti-freeze became that much more diluted, and though we carried a small reserve drum of ethylene glycol its weight diminished perceptibly with every halt we made.

We had, hours before that, dispensed with a lookout, and the burden of all this work fell on Jackstraw, Zagero, Corazzini and myself. Of the four of us, Jackstraw was the only one who escaped what I knew would be permanent injury or disfigurement in the shape of scars and destroyed tissue. Zagero might never before have borne any of the scars of his trade, but he was going to have what looked peculiarly like one now: we had been too late in getting a cold-water compress to his right ear, and these destroyed tissues would need plastic surgery: two of Corazzini's toes had also been left too long without treatment, and I knew that he, too, would finish up in a surgical ward: and, because I was the one most in contact with the engine, my fingertips were a painful bleeding mess, the nails already blackening and beginning to rot away.

Nor were things a great deal better with those inside the tractor cabin. The first physiological effects of the cold were beginning to assert themselves, and assert themselves strongly – the almost overpowering desire for sleep, the uncaring indifference to all that went on around them. Later would come the sleeplessness, the anaemia, the digestive troubles, the nervousness that could lead to insanity – if the cold continued long enough these conditions would inevitably succeed the picture of huddled, lifeless misery that presented itself to me whenever I sought the shelter of the cabin and the agony of returning circulation after my spell at the wheel. Many times I saw the picture that afternoon, and always the picture was the same.

The Senator sat slumped in a corner, a dead man but for the fits of violent shuddering that overtook him at regularly recurring intervals. Mahler appeared to sleep. Mrs Dansby-Gregg and Helene lay huddled in one another's arms – an incredible sight, I thought, but then, next only to death itself, the Arctic was the great leveller, an unparalleled agent in stripping away the pretensions and shoddy veneers of everyday living. I was no great believer in the sudden conversions of human nature, and was pretty certain that, with Mrs Dansby-Gregg, the return to civilisation would coincide with the return to her normal self, and that this moment of common humanity shared by herself and her maid would be no more than a fading and unwelcome memory: but for all my dislike of Mrs Dansby-Gregg, I was beginning to develop more than a sneaking admiration for her. The carefully cherished snobbery, the maddeningly easy and condescending assumption of an inevitable social superiority were irritating enough, heaven knew, but behind that unlovable facade seemed to lie a deep-buried streak of that selflessness which is the hallmark of the genuine aristocrat: although she complained constantly about the tiny irritations, she was silent on matters that caused her genuine suffering: she was developing a certain brusque helpfulness, as if she was half-ashamed of it, and showed a care for her maid which, though probably no more than that feudal kindness that reaches its best in adversity, nevertheless verged almost on tenderness: and I had seen her take a mirror from her handbag, inspect the ravages frostbite had wreaked on her lovely face, then return the mirror to her bag with a gesture of indifference. Mrs Dansby-Gregg, in short, was becoming for me an object lesson against the dangers of an over-ready classification of people into types.