I answered all of their questions as best I could but these answers were all to the same effect, that I didn't really know anything more about it than they did.

"But you said some time ago that you did, perhaps, know one thing more than we did." It was Corazzini who put the question, and he was looking at me shrewdly. "What was that, Dr Mason?"

"What? Ah, yes, I remember now." I hadn't forgotten, but the way things were shaping up in my mind I'd had second thoughts about mentioning it, and had time to think up a plausible alternative. "I need hardly tell you that it's nothing that I actually know, Mr Corazzini—how could I, / wasn't in the plane—just a reasonably informed guess in the absence of all other solutions. It's based on the scientific observations made here and in other IGY stations in Greenland, some of them over the past eighteen months.

"For over a year now, we have been experiencing a period of intense sun-spot activity—that's one of the main interests of the IGY year—the most intense of this century. As you may know, sun-spots, or, rather, the emission of solar particles from these sun-spots, are directly responsible for the formation of the aurora borealis and magnetic storms, both of these being related to disturbances in the ionosphere. These disturbances can and, actually, almost invariably do interfere with radio transmission and reception, and when severe enough can completely disrupt all normal radio communications: and they can also produce temporary alterations of the earth's magnetism which knock magnetic compasses completely out of kilter." All of which was true enough as far as it went. "It would, of course, require extreme conditions to produce these effects: but we have been experiencing these lately, and I'm pretty sure that that's what happened with your plane. Where astral navigation—by the stars, that is—is impossible, as it was on a night like this, you are dependent on radio and compasses as your two main navigational aids: if these are knocked out, what have you left?"

A fresh hubbub of talk arose at this, and though it was quite obvious that most of them had only a vague idea what I was talking about, I could see that this idea was finding a fair degree of ready acceptance, satisfying them and fitting the facts as they knew them. I saw Joss gazing at me with an expressionless face, looked him in the eye for a couple of seconds, then turned away. As a radio operator, Joss knew even better than I that, though there was still some sun-spot activity, it had reached its maximum in the previous year: and as an ex-aircraft radio operator, he knew that airliners flew on gyrocompasses, which neither sun-spots nor magnetic storms could ever affect in the slightest.

"We'll have something to eat now." I cut through the buzz of conversation. "Any volunteers to give Jackstraw a hand?"

"Certainly." Marie LeGarde, as I might have guessed, was first on her feet. "I'm by way of being what you might call a mean cook. Lead me to it, Mr Nielsen."

"Thanks, Joss, you might give me a hand to rig a screen." I nodded at the injured pilot. "We'll see what we can do for this boy here." The stewardess, unbidden, moved forward to help me also. I was on the point of objecting -1 knew that this wasn't going to be nice—but I didn't want trouble with her, not yet. I shrugged my shoulders and let her stay.

Half an hour later, I had done all I could. It indeed hadn't been nice, but both the patient and the stewardess had stood it far better than I had expected. I was fixing and binding on a stiff leather helmet to protect the back of his head and Joss was strapping him down, inside the sleeping-bag, to the stretcher, so that he couldn't toss around and hurt himself, when the stewardess touched my arm.

"What—what do you think now, Dr Mason?"

"It's hard to be sure. I'm not a specialist in brain or head injuries, and even a specialist would hesitate to say. The damage may have penetrated deeper than we think. There may be haemorrhaging—it's often delayed in these cases."

"But if there's no haemorrhaging?" she persisted. "If the damage is no worse than what you think, what you see?"

"Fifty-fifty. I wouldn't have said so a couple of hours ago, but he seems to have quite astonishing powers of resistance and recuperation. Better than an even chance, I would say—if he had the warmth, the food, the skilled nursing he would have in a first class hospital. As it is—well, let's leave it at that, shall we?"

"Yes," she murmured. "Thank you."