'Not… gelignite! Mother of God, Mannix, it's gin!'

A blinding light of understanding hit me. Spirits were illegal and therefore precious in Bir Oassa, a predominantly Arab community. The gelignite was a double bluff, to prevent officials from probing further into Dufour's illicit cargo. Few would tamper with such a load. He had been smuggling alcohol to the oilfields.

And now, instead of the shattering explosion that we'd hoped for there would be at most a small thump, a brief shock. The damage would be to the truck itself. McGrath's heroic, insane act would be all for nothing.

'Oh dear God.'

We stood frozen. Wadzi was hurt but alive and he'd be on his feet again any moment. We were still surrounded by armed men, and there was no path to freedom; nowhere to go. The revolver hung loosely in my hand and I felt sick and stunned. We had gambled and lost.

The truck veered off course, clawing its way across the dirt shoulder of the upper road. It was alongside the rig by now. Its erratic steering could only mean that McGrath was badly wounded or perhaps even already dead. It rocked and shuddered to a halt, dwarfed by the enormous structure of the rig. It half tilted off the shoulder and hung over the edge of the sheer drop to the ferry yard. My heart hammered as I saw a figure inside the cab – my last sight of Mick McGrath.

The truck exploded.

It was not, indeed, a very great event. The truck blew apart in a sheet of flame. The men and other vehicles nearby were sheltered from damage by the rig itself, an object too massive to be affected.

But under the truck was the roadway. Years old, carelessly maintained, potholed and crumbling; at this spot it clung to the hillside over a drought-dry, friable crust of earth knitted together with shallow-rooted vegetation. The road had no more stability than a child's sandpit.

The exploding truck tore this fragile structure like a cobweb.

A cracking fissure ran along the ancient tarmac just where the full weight of the rig already bore down too heavily for safety. There was a gigantic roar, a rolling billow of dust, and the entire hillside gave way under the terrible pressure of the rig.

With its load of the three hundred ton transformer and the coupled tractors the rig began to roll and tumble down the slope towards the ferry yard, dreadful in its power. With it came huge chunks of tarmac, earth, boulders and debris. It thundered downwards, gaining momentum, the air split with the tortured scream of metal and the roar of the landslide that came with it.

Men scattered like ants and fled in horror from the monstrous death racing down towards them. Engines screamed into life, rifles clattered to the ground as the soldiers dashed frantically for safety. The rig crashed with appalling, ponderous strength into the first of the outbuildings, crushing them to matchwood. The paving of the yard crumbled under the onslaught.

We stood in shock and terror as the animal we had led about so tamely turned into a raging brute trumpeting destruction. And then there was a scream wilder than any I'd yet heard.

'No! No! Stop it – don't let it happen – '

Kemp burst between us, his face contorted, his eyes bulging in horror, and ran straight towards the rig. We took a couple of steps after him and stopped, helpless to prevent the awful thing Kemp was about to do.

While all other men fled from the oncoming monster, Kemp held his hands out in front of him in a futile, terrible gesture and ran straight into its path. The juggernaut claimed many bloody sacrifices but one went willingly.

Losing momentum on the flat, the rig halted abruptly. From among crushed and unrecognizable fragments the bulk of the transformer rose twisted but identifiable. Billowing dust merci fully hid details of the trail of carnage. Remnants of one of the ferry buildings leaned drunkenly, ripped open and eviscerated.

My knees were as weak as grass stems and the skin of my face was drawn taut and painful. Hammond was sobbing in a hard, dry fashion that wrenched the breath from his body. Kirilenko was on his knees, gripping a rifle in both hands; the barrel was buckled under the strength he had exerted.

Zimmerman had his hands to his face and blood trickled down where some flying debris had cut him. Dufour and Thorpe stood in total silence; Dufour's arms were wrapped around Ritchie Thorpe's shoulders in a grip of iron. Everyone was white and shattered.

The noise of screams and moaning, voices crying for help, buckling metal and splintering wood were all around us, but we stood in a small oasis of silence. There were no soldiers anywhere near us except Colonel Wadzi himself, who was rocking slightly on his feet, his uniform ripped and dirty, his face haggard with shock.

I took a deep gasp of air.

'Let's get the hell out of here.'

Wadzi raised his face to mine, his eyes bewildered.

'My men…' he said uncertainly, and then more firmly, 'I have much to do. You people, you must go. We do not want you here.'

His voice was drained of every emotion. We were bad news. He had done with us for ever.

Hammond said, 'My God, that poor bloody man.'

I knew he meant Kemp, but it was McGrath I thought of.

Thorpe said softly, 'There's nothing to keep us here now.'

I nodded in complete understanding. Safe from the path of destruction the DUKW was unscathed in its waterside garage.

'Auntie Bess is waiting,' I said. 'Let's go and join the others.'