I estimated that the rig was moving at most a quarter of a mile an hour; it took about six minutes before the whole length of the combine was entirely supported by the bridge. If you were nervous now was the time to hold your breath. I held mine.

Then above the uproar of the airlift engines and the rush of air I heard a faint yell, and someone tugged at my arm. I turned and saw Sadiq's sergeant, his face distorted as he shouted something at me. At my lack of comprehension he pulled my arm again and pointed back along the road leading up to the bridge. I turned and saw a column of vehicles coming up: jeeps and motorcycles at the front and the looming, ugly snouted silhouettes of tanks behind them.

I ran towards them with the sergeant alongside me. As soon as the volume of noise dropped enough to speak and be heard I pulled up and snapped, 'Where's Captain Sadiq?'

The sergeant threw out his hand towards the river. 'On the other side.'

'Christ! Go and get him – fast!'

The sergeant looked dismayed. 'How do I do that?'

'On your feet. Run! There's room for you to pass. Wait. If Mister Kemp, if the road boss sees you he may stop. You signal him to carry on. Like this.' I windmilled my arm, pointing forwards, and saw that the sergeant understood what to do. 'Now go!'

He turned and ran back towards the bridge and I carried on towards the armoured column, my heartbeat noticeably quicker. It's not given to many men to stop an army single-handed, but I'd been given so little time to think out the implications that I acted without much reflection. A leading command car braked to a stop, enveloping me in a cloud of dust, and an angry voice shouted something in Kinguru, or so I supposed. I waved the dust away and shouted, 'I'm sorry, I don't understand. Do you speak English, please?'

An officer stood up in the passenger seat of the open command car, leaning over the windscreen and looking down at the bridge with unbelieving eyes. When he turned his gaze on me his eyes were like flint and his voice gravelly. 'Yes, I speak English. What is going on there?'

'We're taking that load across the bridge. It's going up to the new power plant at Bir Oassa.' «

'Get it off there!' he shouted.

That's what we're doing,' I said equably.

'I mean move it faster,' he shouted again, convulsed with anger. 'We have no time to waste.'

'It's moving as fast as is safe.'

'Safe!' He looked back at his column, then again at me. 'You don't know what that word means, Mister Englishman.' He shouted a string of orders to a motorcyclist who wheeled his bike around and went roaring back up the road. I watched it stop at the leading tank and saw the tank commander lean down from the turret to listen. The tank cut out of the column and ground to a rattling halt alongside the command car. The officer shouted a command and I saw the turret swivel and the barrel of the gun drop slightly.

I was sweating harder now, and drier in the mouth, and I wished to God Sadiq would show up. I looked round hopefully, but of Sadiq or any of his military crowd there was no sign.

'Hey, Captain,' I shouted, giving him as flattering a rank as possible without knowing for sure. 'What are you doing? There are four hundred and thirty tons on that bridge.'

His face cracked into a sarcastic smile. 'I will get it to go faster.'

I sized him up. He was obviously immune to reason, so I would have to counter his threat with a bigger one. I said, 'Captain, if you put a shell even near that rig you'll be likely to lose it and the whole bridge with it. It's worth a few million pounds to your government and Major General Kigonde is personally handling its wellbeing. And I don't think he'd like you to wreck the bridge either.'

He looked baffled and then came back with a countermove of his own. 'I will not fire on the bridge. I will fire into the trucks and the men on the river bank if that thing does not go faster. You tell them.'

His arm was upraised and I knew that if he dropped it fast the tank would fire. I said, 'You mean the airlift truck? That would make things much worse.'

'Airlift? What is that?'

'A kind of hovercraft.' Would he understand that? No matter: at least I could try to blind him with science. 'It is run by the truck just off the bridge and it's the only way of getting the rig across the bridge. You damage it, or do anything to stop our operation and you'll be stuck here permanently instead of only for the next half-hour. Unless you've brought your own bridge with you.'

His arm wavered uncertainly and I pressed on. 'I think you had better consult your superior about this. If you lose the bridge you won't be popular.'

He glared at me and then at last his arm came down, slowly. He dropped into his seat and grabbed the microphone in front of him. The little hairs on the back of my neck lay down as I turned to see what was happening at the bridge.

Sadiq's troops had materialized behind our men and trucks, but in a loose and nonbelligerent order. They were after all not supposed to protect us from their own side, assuming these troops were still their own side. Beyond them the rig still inched its way painfully along as Kemp stuck to the job in hand. Sadiq was standing on the running board of one of his own trucks and it roared up the road towards us, smothering me in yet another dust bath on its arrival. Before it had stopped Sadiq had jumped down and made straight for the officer in the command car.

Captain Whoosit was spoiling for a fight and Sadiq didn't outrank him, but before a row could develop another command car arrived and from it stepped a man who could only have been the battalion commander, complete with Sam Browne belt in the British tradition.

He looked bleakly around him, studied the bridge through binoculars, and then conferred with Sadiq, who was standing rigidly to attention. At one point Mr Big asked a question and jabbed a finger towards me. I approached uninvited as Sadiq was beginning to explain my presence. 'I can speak for myself, Captain. Good morning, Colonel. I'm Neil Mannix, representing British Electric. That's our transformer down there.'

He asked no further questions. I thought that he already knew all about us, as any good commander should. 'You must get it out of our way quickly,' he said.

'It's moving all the time,' I said reasonably.

The Colonel asked, 'Does the driver have a radio?'

'Yes, sir,' said Sadiq. A pity; I might have said the opposite.

Talk to him. Tell him to move faster. Use my radio.' He indicated his own command car, but as Sadiq moved to comply I said, 'Let me talk to him, Colonel. He will accept my instructions easier.'

'Very well, Mister Mannix. I will listen.'

I waited while Sadiq got on net with Kemp and then took the mike. 'Basil, this is Neil Mannix here. Do you read me? Over.'

'Yes, Neil. What's going on back there? Over.'

'Listen and don't speak. There is an army detachment here which needs to use the bridge urgently. I assume you are moving at designated speed? It will be necessary for you to increase to the -'

The Colonel interrupted me. 'What is this designated speed?'

'Hold it. Over. It works out about a mile an hour, Colonel.' I ignored his stricken face and went on into the mike, 'Basil? Increase if necessary. How long do you estimate as of now? Over.'

'Fifteen minutes, perhaps twenty. Over.'

Taking his cue, Kemp was giving answers only. He could pick up clues pretty smartly. There was no such thing as a designated speed and Kemp knew this. I went on, 'Get it down to no more than fifteen, ten if possible. Over.'

I was praying for an interruption and for once I got lucky. Sadiq's military unit had got restless and several vehicles, including those carrying the guns, started down the road towards us. The commander turned alertly to see what was going on. In that moment, with nobody listening except the Colonel's driver, I said hastily, 'Basil, if you don't get the hell off that bridge we'll have shells coming up our ass. These guys are trigger-happy. Go man go. Acknowledge formally. Over.'