Musallim interrupted, 'That must have been before the Riqaishi was Governor of Ibri. I had been there myself the year before. Sahail was with me and we went there from...'

But al Auf went on, 'I was riding the three-year-old I had bought from bin Duailan.'

'The one the Manahil raided from the Yam?' Bin Kabina asked.

'Yes. I exchanged it later for the yellow six-year-old I got from bin Ham. Janazil rode a Batina camel. Do you remember her? She was the daughter of the famous grey which belonged to Harahaish of the Wahiba.'

Mabkhaut said, 'Yes, I saw her last year when he was in Salala, a tall animal; she was old when I saw her, past her prime but even then a real beauty.'

Al Auf went on, 'We spent the night with Rai of the Afar.'

Bin Kabina chimed in, 'I met him last year when he came to Habarut; he carried a rifle, "a father of ten shots", which he had taken from the Mahra he had killed in the Ghudun. Bin Mautlauq offered him the grey yearling, the daughter of Farha, and fifty riyals for this rifle, but he refused.'

Al Auf continued, 'Rai killed a goat for our dinner and told us ...', but I interrupted: 'Yes, but how many days did it take you to get to Bai?' He looked at me in surprise and said, 'Am I not telling you?'

We stopped at sunset for the evening meal, and fed to our camels the tribulus we had brought with us. All the skins were sweating and we were worried about our water. There had been a regular and ominous drip from them throughout the day, a drop falling on to the sand every few yards as we rode along, like blood dripping from a wound that could not be staunched. There was nothing to do but to press on, and yet to push the camels too hard would be to founder them. They were already showing signs of thirst. Al Auf had decided to go on again after we had fed, and while Musallim and bin Kabina baked bread I asked him about his former journeys through these Sands. 'I have crossed them twice,' he said. 'The last time I came this way was two years ago. I was coming from Abu Dhabi.' I asked, 'Who was with you?' and he answered, 'I was alone.' Thinking that I must have misunderstood him, I repeated, 'Who were your companions?' 'God was my companion.' To have ridden alone through this appalling desolation was an incredible achievement. We were travelling through it now, but we carried our own world with us: a small world of five people, which yet provided each of us with companionship, with talk and laughter and the knowledge that others were there to share the hardship and the danger. I knew that if I travelled here alone the weight of this vast solitude would crush me utterly.

I ALSO KNEW that al Auf had used no figure of speech when he said that God was his companion. To these Bedu, God is a reality, and the conviction of his presence gives them the courage to endure. For them to doubt his existence would be as inconceivable as for them to blaspheme. Most of them pray regularly, and many keep the fast of Ramadhan, which lasts for a whole month, during which time a man may not eat or drink from dawn till sunset. When this fast falls in summer - and the Arab months being lunar it is eleven days earlier each year - they make use of the exemption which allows travellers to observe the fast when they have finished their journey, and keep it in the winter. Several of the Arabs whom we had left at Mughshin were fasting to compensate for not having done so earlier in the year. I have heard townsmen and villagers in the Hadhramaut and the Hajaz disparage the Bedu, as being without religion. When I have protested, they have said, 'Even if they pray, their prayers are not acceptable to God, since they do not first perform the proper ablutions.'

These Bedu are not fanatical. Once I was travelling with a large party of Rashid, one of whom said to me, 'Why don't you become a Muslim and then you would really be one of us?' I answered, 'God protect me from the Devil!' They laughed. This invocation is one which Arabs invariably use in rejecting something shameful or indecent. I would not have dared to make it if other Arabs had asked me this question, but the man who had spoken would certainly have used it if I had suggested that he should become a Christian.

After the meal we rode for two hours along a salt-flat. The dunes on either side, colourless in the moonlight, seemed higher by night than by day. The lighted slopes looked very smooth, the shadows in their folds inky black. Soon I was shivering uncontrollably from the cold. The others roared out their songs into a silence, broken otherwise only by the crunch of salt beneath the camels' feet. The words were the words of the south, but the rhythm and intonation were the same as in the songs which I had heard other Bedu singing in the Syrian desert. At first sight the Bedu of southern Arabia had appeared to be very different from those of the north, but I now realized that his difference was largely superficial and due to the clothes which they wore. My companions would not have felt out of place in an encampment of the Rualla, whereas a townsman from Aden or Muscat would be conspicuous in Damascus.

Eventually we halted and I dismounted numbly. I would have given much for a hot drink but I knew that I must wait eighteen hours for that. We lit a small fire and warmed ourselves before we slept, though I slept little. I was tired; for days I had ridden long hours on a rough camel, my body racked by its uneven gait. I suppose I was weak from hunger, for the food which we ate was a starvation ration, even by Bedu standards. But my thirst troubled me most; it was not bad enough really to distress me but I was always conscious of it. Even when I was asleep I dreamt of racing streams of ice-cold water, but it was difficult to get to sleep. Now I lay there trying to estimate the distance we had covered and the distance that still lay ahead. When I had asked al Auf how far it was to the well, he had answered, 'It is not the distance but the great dunes of the Uruq al Shaiba that may destroy us.' I worried about the water which I had watched dripping away on to the sand, and about the state of our camels. They were there, close beside me in the dark. I sat up and looked at them. Mabkhaut stirred and called out, 'What is it, Umbarak?' I mumbled an answer and lay down again. Then I worried whether we had tied the mouth of the skin properly when we had last drawn water and wondered what would happen if one of us was sick or had an accident. It was easy to banish these thoughts in daylight, less easy in the lonely darkness. Then I thought of al Auf travelling here alone and felt ashamed.

The others were awake at the first light, anxious to push on while it was still cold. The camels sniffed at the withered tribulus but were too thirsty to eat it. In a few minutes we were ready. We plodded along in silence. My eyes watered with the cold ; the jagged salt-crusts cut and stung my feet. The world was grey and dreary. Then gradually the peaks ahead of us stood out against a paling sky; almost imperceptibly they began to glow, borrowing the colours of the sunrise which touched their crests.

A high unbroken dune-chain stretched across our front. It was not of uniform height, but, like a mountain range, consisted of peaks and connecting passes. Several of the summits appeared to be seven hundred feet above the salt-flat on which we stood. The southern face confronting us was very steep, which meant that this was the lee side to the prevailing winds. I wished we had to climb it from the opposite direction, for it is easy to take a camel down these precipices of sand but always difficult to find a way up them.

Al Auf told us to wait while he went to reconnoitre. I watched him walking away across the glistening salt-flat, his rifle on his shoulder and his head thrown back as he scanned the slopes above. He looked superbly confident, but as I viewed this wall of sand I despaired that we would ever get the camels up it. Mabkhaut evidently thought the same, for he said to Musallim, 'We will have to find a way round. No camel will ever climb that.' Musallim answered, 'it is al Auf's doing. He brought us here. We should have gone much farther to the west, nearer to Dakaka.' He had caught a cold and was snuffling, and his rather high- pitched voice was hoarse and edged with grievance. I knew that he was jealous of al Auf and always ready to disparage him, so unwisely I gibed, 'We should have got a long way if you had been our guide!' He swung round and answered angrily, 'You don't like the Bait Kathir, I know that you only like the Rashid. I defied my tribe to bring you here and you never recognize what I have done for you.'

For the past few days he had taken every opportunity of reminding me that I could not have come on from Ramlat al Ghafa without him. It was done in the hope of currying favour and of increasing his reward, but it only irritated me. Now I was tempted to seek relief in angry words, to welcome the silly, bitter squabble which would result. I kept silent with an effort and moved apart on the excuse of taking a photograph. I knew how easily, under conditions such as these, I could take a violent dislike to one member of the party and use him as my private scapegoat. I thought, 'I must not let myself dislike him. After all, I do owe him a great deal; but I wish to God he would not go on reminding me of it.'

I WENT OVER TO A BANK and sat down to wait for al Auf's return. The ground was still cold, although the sun was now well up, throwing a hard, clear light on the barrier of sand ahead of us. It seemed fantastic that this great rampart which shut out half the sky could be made of wind- blown sand, Now I could see al Auf, about half a mile away, moving along the salt-flat at the bottom of the dune. While I watched him he started to climb a ridge, like a mountaineer struggling upward through soft snow towards a pass over a high mountain. I even saw the tracks which he left behind him. He was the only moving thing in all that empty, silent landscape.

What were we going to do if we could not get the camels over it? I knew that we could not go any farther to the east, for al Auf had told me that the quicksands of Umm al Samim were in that direction. To the west the easier sands of Dakaka, where Thomas had crossed, were more than two hundred miles away. We had no margin, and could not afford to lengthen our journey. Our water was already dangerously short, and even more urgent than our own needs were those of the camels, which would collapse unless they were watered soon. We must get them over this monstrous dune, if necessary by unloading them and carrying the loads to the top. But what was on the other side? How many more of these dunes were there ahead of us? If we turned back now we might reach Mughshin, but I knew that once we crossed this dune the camels would be too tired and thirsty to get back even to Ghanim. Then I thought of Sultan and the others who had deserted us, and of their triumph if we gave up and returned defeated. Looking again at the dune ahead I noticed that al Auf was coming back. A shadow fell across the sand beside me. I glanced up and bin Kabina stood there. He smiled, said 'Salam AIaikum', and sat down. Urgently I turned to him and asked, 'Will we ever get the camels over that?' He pushed the hair back from his forehead, looked thoughtfully at the slopes above us, and answered, 'It is very steep but al Auf will find a way. He is a Rashid; he is not like these Bait Kathir.' Unconcernedly he then took the bolt out of his rifle and began to clean it with the hem of his shirt, while he asked me if all the English used the same kind of rifle.

When al Auf approached we went over to the others. Mabkhaut's camel had lain down; the rest of them stood where we had left them, which was a bad sign. Ordinarily they would have roamed off at once to look for food. Al Auf smiled at me as he came up but said nothing, and no one questioned him. Noticing that my camel's load was unbalanced he heaved up the saddlebag from one side, and then picking up with his toes the camel-stick which he had dropped, he went over to his own camel, caught hold of its head-rope, said 'Come on', and led us forward.

It was now that he really showed his skill. He picked his way unerringly, choosing the inclines up which the camels could climb. Here on the lee side of this range a succession of great faces flowed down in unruffled sheets of sand, from the top to the very bottom of the dune. They were unscalable, for the sand was poised always on the verge of avalanching, but they were flanked by ridges where the sand was firmer and the inclines easier. It was possible to force a circuitous way up these slopes, but not all were practicable for camels, and from below it was difficult to judge their steepness. Very slowly, a foot at a time, we coaxed the unwilling beasts upward. Each time we stopped I looked up at the crests where the rising wind was blowing streamers of sand into the void, and wondered how we should ever reach the top. Suddenly we were there. Before slumping down on the sand I looked anxiously ahead of us. To my relief I saw that we were on the edge of rolling downs, where the going would be easy among shallow valleys and low, rounded hills. 'We have made it. We are on top of Uruq al Shaiba', I thought triumphantly. The fear of this great obstacle had lain like a shadow on my mind ever since al Auf had first warned me of it, the night we spoke together in the sands of Ghanim. Now the shadow had lifted and I was confident of success.

We rested for a while on the sand, not troubling to talk, until al Auf rose to his feet and said 'Come on'. Some small dunes built up by cross-winds ran in curves parallel with the main face across the back of these downs. Their steep faces were to the north and the camels slithered down them without difficulty. These downs were brick-red, splashed with deeper shades of colour; the underlying sand, exposed where it had been churned up by our feet, showing red of a paler shade. But the most curious feature was a number of deep craters resembling giant hoof- prints. These were unlike normal crescent-dunes, since they did not rise above their surroundings, but formed hollows in the floor of hard undulating sand. The salt-flats far below us looked very white.

We mounted our camels. My companions had muffled their faces in their head-cloths and rode in silence, swaying to the camels' stride. The shadows on the sand were very blue, of the same tone as the sky; two ravens flew northward, croaking as they passed. I struggled to keep awake. The only sound was made by the slap of the camels' feet, like wavelets lapping on a beach.

To rest the camels we stopped for four hours in the late afternoon an a long gentle slope which stretched down to another salt-flat. There was no vegetation on it and no saltbushes bordered the plain below us. Al Auf announced that we would go on again at sunset. While we were feeding I said we won to him cheerfully, 'Anyway, the worst should be over now that we are across the Uruq al Shaiba.' He looked at me for a moment and then answered, 'If we go well tonight we should reach them tomorrow.' I said, 'Reach what?' and he replied, 'The Uruq al Shaiba', adding, 'Did you think what we crossed today was the Uruq al Shaiba? That was only a dune. You will see them tomorrow.' For a moment, I thought he was joking, and then I realized that he was serious, that the worst of the journey which I had thought was behind us was still ahead.

It was midnight when at last al Auf said, 'Let's stop here. We will get some sleep and give the camels a rest. The Uruq al Shaiba are not far away now.' In my dreams that night they towered above us higher than the Himalayas.