Erik was paralysed with horror. In medical school he had not had to deal with maimed and bleeding bodies. He was used to corpses in anatomy class – they had had one between two students, and he and Hermann had shared the cadaver of a shrivelled old woman – and he had watched living people being cut open on the operating table. But none of that had prepared him for this.

He wanted nothing but to run away.

He turned around. His mind was blank of every thought but fear. He started to walk back the way they had come, towards the forest, away from the battle, taking long, determined strides.

Hermann saved him. He stood in front of Erik and said: ‘Where are you going? Don’t be a fool!’ Erik kept moving, and tried to walk past him. Hermann punched him in the stomach, really hard, and Erik folded over and fell to his knees.

‘Don’t run away!’ Hermann said urgently. ‘You’ll be shot for desertion! Pull yourself together!’

While Erik was trying to catch his breath he came to his senses. He could not run away, he must not desert, he had to stay here, he realized. Slowly his willpower overcame his terror. Eventually he got to his feet.

Hermann looked at him warily.

‘Sorry,’ said Erik. ‘I panicked. I’m all right now.’

‘Then pick up the stretcher and keep going.’

Erik picked up the rolled stretcher, balanced it on his shoulder, turned around and ran on.

Closer to the river, Erik and Hermann found themselves among infantry. Some were manhandling inflated rubber dinghies out of the backs of trucks and carrying them to the water’s edge, while the tanks tried to cover them by firing at the French defences. But Erik, rapidly recovering his mental powers, soon saw that it was a losing battle: the French were behind walls and inside buildings, while the German infantry were exposed on the bank of the river. As soon as they got a dinghy into the water, it came under intense machine-gun fire.

Upstream, the river turned a right-angled bend, so the infantry could not move out of range of the French without retreating a long distance.

There were already many dead and wounded men on the ground.

‘Let’s pick this one up,’ Hermann said decisively, and Erik bent to the task. They unrolled their stretcher on the ground next to a groaning infantryman. Erik gave him water from a flask, as he had learned in training. The man seemed to have numerous superficial wounds on his face and one limp arm. Erik guessed he had been hit by machine-gun fire that luckily had missed his vital areas. He saw no gush of blood, so they did not attempt to staunch his wounds. They lifted the man on to the stretcher, picked it up, and began to jog back to the dressing station.

The wounded man cried out in agony as they moved; then, when they stopped, he shouted: ‘Keep going, keep going!’ and gritted his teeth.