The arcing tracer fire cut its devastating swathe across the enemy position, slicing and dicing as it went. He saw a dark figure stagger, throw up his weapon and crumple to the ground; then another; then another. To Ben’s right, the crashing single shots of Baldacci’s rifle and the rat-tat of the M4s were a huge, sense-numbing, ear-splitting symphony of chaos and confusion. Holt rattled off most of a thirty-round magazine and then started pumping incendiary grenades, lighting up the night with a rain of fire and explosions that cleared out the nooks and crannies where more of the Taliban fighters were hiding.

The sudden, ferocious onslaught from on high had a stunning effect on the enemy, who after a disorganised defence lasting no more than about ninety seconds broke from their positions – those who still could break from them – and beat a retreat down the valley, rattling off an inaccurate return fire as they went. One or two shots ricocheted near Ben and Wolf’s position; soon the shooting stopped altogether. Then they were gone, but not before eighteen of them were lying dead among the rocks.

‘That ought to do it,’ Wolf said in the deafened silence.

The attack might have been thwarted but the fighters would be back, and in far greater numbers if they were still within radio range of the rest of their people. ‘Come on,’ Ben said, grabbing the Maximi and first on his feet without waiting for Holt to give the green light. With Wolf right behind him he led the way down towards where the three surviving British soldiers were emerging from their cover. They peered uncertainly upwards and shouldered their rifles as the unexpected visitors scrambled down the rocks towards them. In their confusion they might easily have started shooting off whatever ammo they had left. Ben waved and called out in a loud, clear voice for them to hold their fire, and they hesitantly lowered their weapons.

But as Ben made his way down the loose slope, he could see that something wasn’t quite right with the soldiers. Of course it was a shocking and nerve-shredding experience to be pinned under enemy fire with every likelihood of getting killed. Even more so when two of your comrades were already down. But that still didn’t account for the way the soldiers seemed to be staggering unsteadily about. They didn’t move like injured men. It was something else.