Heck laughed. ‘You know, Professor, I’m growing to like you. If I had a bottle of hooch it would be all yours, but I’m afraid I’ve nothing to give you but water. Oh, but I got these.’ He fished the last of his cigarettes from his shirt pocket and tapped out a couple. ‘I think you deserve one, don’t you?’

‘No, thanks, I’ll wait for the whisky.’

They took the rest of the mountain road at a sedate pace. Heck put his feet up and smoked. At the bottom, where the mountain track joined the main valley road, they stopped and looked back towards the ravine where the two trucks had ended up. All they could see was the occasional lick of flame and the plume of black smoke.

Wilde switched off the engine.

‘What are you doing, Professor?’

‘I have to go and see.’

‘No one could have survived that. Leave it to the locals – or the French. They must patrol this road, so they’ll find it soon enough. God knows how they’ll get to it, though. Must be a mile across impossible terrain.’

Wilde shrugged. ‘I have to look.’ He climbed from the road down a shallow incline of rock to a meadow. Cows turned to gaze at him without much enthusiasm or interest, their bells clanging and carrying on the breeze. He turned briefly and saw that Heck was following him. He waited for him, then they walked together, descending to a fast-flowing river and following its path towards the smoke.

It took them half an hour to reach the wreckage. The hike had not been as difficult as anticipated. The fire had burnt out, but smoke still spiralled from the blackened metal skeletons. The timber lorry’s driver was still in his cab, his charred corpse slumped across the wheel, almost unrecognisable as a human being. The driver of the other vehicle had been thrown clear and lay fifty yards away, untouched by fire. He was old, well over sixty with thin grey hair. His age-lined eyes were open, staring sightlessly up through the smoke to the blue of the sky. His face seemed unmarked by the fall.

Wilde half wondered whether he might be one of the elderly men they had seen in the Kuhhaus pension at Grünegg the night before, but the face meant nothing. He felt for a pulse but didn’t find one. Then he turned him over and saw that the man’s ancient skull had been broken open like an egg, his brains spilling out.

‘Dead,’ Wilde said.

‘Well, there’s a surprise, Professor.’

He stared, frowning, at Heck’s eyes. ‘Are you really as callous as you make out, Lieutenant? Or is this just some game you’ve decided to play with me?’