'And the plane?' Paul's voice was shrill.

'Is about three kilometres north-west of the split column.'

It was chancy. Atitel's idea of north-west might not coincide with Byrne's compass, and I didn't like the sound of that 'about three kilometres' – it could be anything from two to four, more or less. I figured we might have to search five or six square kilometres. Still, it was better than the situation I had envisaged when talking to Paul.

I said, 'Can you guide us back to Tamrit? I don't know that I could.'

'Yeah. I've been taking compass bearings.' Byrne looked from me to Paul. 'Well, what about it?'

Paul nodded vigorously, so I shrugged. If it was a question of taking a vote I was out-voted. I said, 'It's all right with me as long as Atitel will be okay. It's a long way back to Tamrit and then he'll have to wait alone while Hami goes down that bloody ravine and on into Djanet. Do you think it's fair on him?'

'It's his idea,' said Byrne. 'He don't mind the broken leg just as long as he can get it set properly. He says he's broken that leg before. What he's really worried about is his ten goddamned camels. He wants them.'

'Then tell him to pray to Allah that this is the aeroplane we're looking for.'

We redistributed loads on the donkeys and then the two Tuareg went back, with Atitel riding a donkey led by Hami, his splinted leg sticking out grotesquely at right-angles. Then there were just the three of us left with five donkeys. I led two and so did Paul, while Byrne coped with one so that he could have a hand free for his compass.

I was mildly surprised when we saw Atitel's landmark after a two-hour march. It didn't seem possible that things could go right for us -1 had half expected that we'd have to search for the damn thing – but there it stood unmistakably as Byrne had described it, a tall tower which looked as though a giant had taken a swipe at it with an axe and had cleft it from the top.

We camped at its base. Paul was all for going on the further three kilometres to the north-west but Byrne wouldn't have it. 'It's late,' he said 'I didn't mind night marches with Atitel; I trusted him. But any one of us could bust a leg in the dark. We'll leave it until morning.'

So we left it until morning and breakfasted before dawn, then set out as soon as it was light enough to see clearly. In all my years, even in the army, there was never a period during which I made as many dawn starts as in the desert. We marched three kilometres, Byrne setting the direction and pacing us. That took an hour. Then we stopped in the middle of nowhere and unloaded the donkeys and hobbled them so they wouldn't stray.

The landscape was anarchic; a disorder of rock columns, a hugger-mugger of hiding places. Peter Billson's plane could be within a hundred yards but there was no way of knowing. I said into silence, 'It could have burnt out.'

'No,' said Byrne. 'Atitel said it was intact. He's seen planes before at the airstrip at In Debiren and he said that this plane still had its wings on. He said it was exactly like the plane in the picture.'

'That's incredible! You mean Billson landed in the middle of all this in the dark without bending anything. I don't believe it.'

'He was a good pilot,' protested Paul.

'I don't care if he could fly as well as the Archangel Gabriel – it still seems bloody impossible.'

'Maybe the angeloussen helped him,' said Byrne. 'Now, we've got to do this real careful. No one goes off alone. We keep in sight or sound of each other. If you're out of sight keep hollering.' He stared at Paul. 'In this mess a guy can get lost awful easy so mind what I say.'

Paul mumbled assent. He was quivering like an eager dog who wanted to go and chase rabbits. I said, 'I didn't look at those photocopies too closely. How big is this Northrop?'

'Forty-eight feet wingspan,' said Paul. 'Length, thirty-two feet. Maximum height, nine feet'

It was bigger than I had assumed. We were looking for something in an area of, say, fifteen hundred square feet I felt a bit better, but not much.

'We spread out in a line, Paul in the middle,' said Byrne. 'And you take your direction from me.'

And so began the search. We quartered the area in overlapping sweeps so as not to miss anything, and it was damned hard work. This was not a mere matter of making a march; we had to cover and inspect an area, which meant scrambling over rocks and looking behind every column in that broken wilderness.

We searched all day without finding anything but rocks.

That night Paul was dispirited. He huddled in his djellaba and aimlessly tossed a stone from one hand to the other while staring blankly with unmoving eyes. I didn't feel too good myself and said to Byrne, 'What do you think?'

He shrugged. 'Maybe Atitel was out in his distance and direction. We'll look again tomorrow. Get some sleep.'

'God!' I said. Talk about needles in haystacks. And there's that proverb about leaving no bloody stone unturned.'

Byrne grunted. 'If it was easy to see it would have been found years ago. Atitel says he came on it only by chance four years ago. He'd come up here trying to trap wild camel foals and got himself lost.'

'Why didn't he report it when he got back to Djanet?'

'It didn't mean that much to him. If there had been a body he might have, but he said there was no body near.'

'Do you think Billson tried to walk out?'

'He was a damned fool if he did.'

Paul came alive. 'He wouldn't try that,' he said positively. 'He knew the rules about that. All the pilots in the race were told to stay by the plane if they came down.'

'Yeah,' said Byrne. 'It's the sensible thing to do and, from what I've heard of him, Peter Billson was a sensible guy.' He paused. 'Sorry to bring this up, Paul; but when Atitel told me there was no body I had my doubts about this being the right airplane. What in hell would a good flier like your old man be doing way over here anyway? He'd be off course by nearly two hundred miles.'

'Atitel identified the plane,' said Paul obstinately.

'Yeah, but when I first suggested the Tassili you said yourself your father was too good a pilot to be fifteen degrees out.'

It was all very depressing.

We found it next morning only ten minutes after restarting the search. I found it, and it was infuriating to think that if Byrne hadn't called off the search the previous night another ten minutes would have done it.

I scaled the side of a pillar of rock that had fallen intact and walked across it to see what was on the other side. There, in a sixty-foot-wide gully was an aeroplane looking as pristine as though it had just been delivered from the manufacturer. It stood in that incongruous place as it might have stood on the tarmac outside a hangar.

'Luke!' I yelled. 'Paul! It's here!'

I scrambled down to it, and they both arrived breathless. 'That's it!' shouted Paul. That's my father's plane.' I looked at Byrne. 'Is it?'

'It's a Northrop "Gamma",' he said, and passed his hand almost reverentially over the fuselage. 'Yeah, this is Peter Billson's plane. Look!'

Over forty years of wind-driven sand had worn away the painted registration marks but on the fuselage one could still detect the outline of the letters which made up a word – Flyaway.

'Oh, God!' said Paul, and leaned on the trailing edge of the wing. Suddenly he burst into tears. All the pent-up emotion of a lifetime came out of him in one rush and he just stood there and wept, racked with sobs. To those brought up in our stiff-upper-lip society the sight of a man in tears is apt to be unnerving, so Byrne and I tactfully walked away until Paul could get a grip on himself.

We walked a little way down the gully away from the plane, then Byrne turned and said, 'Now how in hell did he put it down there?' There was wonder in his voice.