At this season, the grazing lands were covered by snow, so we could not see how the verdure thinned out as we went eastward. But we knew it did so, because the ground under the snow got pebbly, then rocky, and the villages ceased to be, and there was only an infrequent and inadequate karwansarai along the trail. After we had passed the last village, a cluster of piled-stone huts which called itself Keshem, in the foothills preceding the mountains, we had to make our own stopping places perhaps three nights out of four. That was not an idyllic way to live, sleeping under tents and under our chapons in snow and chill and wind, and generally having to dine on dried or salted travel rations.

We had worried that the outdoor life would be especially hard on Uncle Mafio. But he made no complaint even when we healthier ones did. He maintained that he was feeling better in that sharp, cold air, as the Hakim Khosro had predicted, and his cough had lessened and did not lately bring up any blood. He allowed the rest of us to take over what heavy work had to be done, but he would not let us shorten the marches on his account, and each day he sat his saddle or, on the rougher stretches, walked beside his horse, as indefatigably as any of us. We were not hurrying, anyway, for we knew we would have to halt for the rest of the winter as soon as we came up against the mountain ramparts. Also, after a while on that hard trail, living on hard rations, the rest of us were nearly as gaunt as Uncle Mafio was, and not eager to exert ourselves. Only Nostril kept his paunch, but it looked now less integral to him, like a separate melon he was carrying under his clothes.

When we came to the Ab-e-Panj River, we followed its broad valley upstream to the eastward, and from then on we were going uphill, ever higher above the level of the rest of the world. To speak of a valley ordinarily brings to mind a depression in the earth, but that one is many farsakhs wide and is lower only in relation to the mountains that rise far off on either side of it. If it were anywhere else in the world, that valley would not be on the world, but immeasurably far above it, high among the clouds, unseeable by mortal eyes, unattainable, like Heaven. Not that the valley resembles Heaven in any way, I hasten to say, it being cold and hard and inhospitable, not balmy and soft and welcoming.

The landscape was unvarying: the wide valley of tumbled rocks and scrub growth, all humped under quilts of snow; the white-water river running through; and far away on both sides the tooth-white, tooth-sharp mountains. Nothing ever changed there but the light, which ranged from sunrises colored like gilded peaches to sunsets colored like roses on fire, and, in between, skies so blue they were near to purple, except when the valley was roofed by clouds of wet gray wool wringing out snow or sleet.

The ground was nowhere level, being all a clutter of boulders and rocks and talus that we had to thread our way around or gingerly make our way across. But, apart from those ups and downs, our continuous climb was imperceptible to our sight, and we might almost have supposed that we were still on the plains. For, each night when we stopped to camp, the mountains on either horizon seemed identically high to those of the night before. But that was only because the mountains were getting higher, the farther we climbed that up-sloping valley. It was like going up a staircase where the banister always keeps pace with you and, if you do not look over, you do not realize that everything beyond is dropping down and away from you.

Nevertheless, we had various means of knowing that we were climbing all the time. One was the behavior of our horses. We two-legged creatures, when we occasionally dismounted to walk for a while, might not have been physically aware that each step forward was also a trifle higher, but the animals with legs fore and aft knew well that they always stood or moved at an incline. And, horses having good sense, they slyly exaggerated their trudging walk to make it seem a plodding labor, so that we would not press them to move faster.

Another indicator of the climb was the river running the length of the valley. The Ab-e-Panj, we had been told, is one of the headwater sources of the Oxus, that great river which Alexander crossed and recrossed, and in his Book it is described as immensely broad and slow-running and tranquil. However, that is far to the west and downhill of where we were now. The Ab-e-Panj alongside our trail was not wide nor deep, but it raced through that valley like an endless stampede of white horses, tossing white manes and tails. It even sounded sometimes more like a stampede than a river, the noise of its cascading water being often lost in the scrape and grate and rumble of the sizable boulders it rolled and jostled along its bed. A blind man could have told that the Abe-Panj was hurtling downhill and, for it to have such momentum, the river’s uphill end had to be somewhere far higher yet. In this winter season, certainly, the river could not for a moment have slowed its tumultuous pace, or it would have frozen solid, and there might not have existed any Oxus downstream. This was apparent, because every splash and spatter and lick of the water on the rock banks instantly turned to blue-white ice. Since that made the footing close to the river even more treacherous than the snow-covered ground—and also because every splash of the water that reached us froze on our horses’ legs and flanks, or on ours—we kept our trail well to one side of the river wherever we could.

Still another indicator of our continuous climb was the noticeable thinning of the very air. Now, I have been often disbelieved, and even jeered, when I have told of this to non-journeyers. I know as well as they do that air is weightless at all times, impalpable except when it moves as wind. When the disbelievers demanded to know how an element without the least weight can have less weight yet, I cannot tell them how, or why; I only know it does. It gets less and less substantial in those upland heights, and there are evidences to show it.

For one, a man has to breathe deeper to fill his lungs. This is not the panting occasioned by fast movement or brisk exercise; a man standing still has to do it. When I exerted myself—loading a horse’s packsaddle, say, or clambering over a boulder blocking the trail—I had to breathe so fast and hard and deep that it seemed I never would get enough air into me to sustain me. Some disbelievers have dismissed that as a delusion fostered by tedium and hardship, of which God knows we had enough to contend with, but I maintain that the insubstantial air was a very real thing. I will additionally adduce the fact that Uncle Mafio, though he like all of us had to breathe deep, was not so frequently or painfully afflicted by the need to cough. Clearly, the thin air of the heights lay not so heavily in his lungs and did not so often have to be forcibly expelled.

I have other evidence. Fire and air, both being weightless, are the closest-related of the four elements; everybody will concede that. And in the high lands where the air is feebler, so is fire. It burns more blue and dim than yellow and bright. This was not just a result of our having to burn the local burtsa shrub for fuel; I experimented with burning other and more familiar things, like paper, and the resultant flame was equally debile and languid. Even when we had a well-fueled and well-laid camp fire, it took longer to char a piece of meat or to boil a pot of water than it had done in lower lands. Not only that, the boiling water also took longer than customary to cook something put into it.

In that winter season, there were no great karwan trains on the trail, but we did meet an occasional other traveling party. Most of these were hunters and trappers of furs, moving from place to place in the mountains. The winter was their working season, and in the clement springtime they would take their accumulated stores of hides and pelts down to market in one of the lowland towns. Their shaggy little packhorses were heaped with the baled pelts of fox, wolf, pard, the urial, which is a wild sheep, and the goral, which is something between a goat and a qazèl. The hunter-trappers told us that this valley which we were climbing was called the Wakhan—or sometimes the Wakhan Corridor, because many mountain passes open off it on all sides, like doors off a corridor, and the valley constitutes both the border between and the access to all the lands beyond. To the south, they said, were passes leading out of the Corridor to lands called Chitral and Hunza and Kashmir, in the east leading to a land called To-Bhot, and in the north to the land of Tazhikistan.