kilometre, Kammler assured them, right the way through to the other side of the mountain. This was Tunnel B. Tunnel A, which ran parallel to it, was almost completed. Cross-tunnels linked the two galleries. The place had been a gypsum mine before the war, and after that a storage site for fuel and poison gas. The first task would be to clear it thoroughly, and that phase was already under way. In the semi-darkness, phantom figures in striped uniforms staggered under the weight of cement sacks, steel girders, wooden prop supports, metal drums. The showering white sparks of the oxyacetylene cutters, dismantling the gasoline storage tanks, spurted at intervals in the gloom. Next, continued Kammler, they would dig and blast out further cross-tunnels and lay a rail line, build a railway station. Eventually the components for the missiles would be brought in by locomotive at one end of the complex, and finished rockets would be taken away on flatbed trucks at the other. The production capacity would be nine hundred missiles per month, the entire process to be undertaken three hundred metres beneath the mountain, invisible to the enemy’s reconnaissance flights and impervious to his bombers. Production would be the responsibility of General Degenkolb, the railway tsar, who had made his reputation mass-manufacturing locomotives.
‘And when will production begin?’
‘January.’
One of the engineers whistled. Von Braun said, ‘The rocket is an extremely complicated mechanism, Brigadeführer. The machine tools require high precision and skilled machinists. Tomorrow is the first day of September. How can a factory be completed at such speed?’
‘By the utilisation of the one resource in which Germany possesses an undoubted surplus capacity.’
‘Which is what?’
‘Manpower.’ Kammler clapped his hands and laughed at their dumbfounded expressions. ‘Come now, gentlemen! If the pharaohs could build their pyramids two and a half thousand years before the birth of Christ, I can assure you the SS is capable of constructing a factory in the middle of the twentieth century and having it fully operational within four months.’
‘How much manpower are you contemplating?’
‘For the construction of the factory and the eventual production?’ Kammler’s hand circled the air. ‘Twenty thousand men. Thirty thousand.’ He shrugged. ‘However many it takes. The reservoir is inexhaustible.’
As they walked back towards the tunnel mouth, Graf asked him if he had ever built anything else of similar size under such pressure of time. ‘Oh yes. In the East. The reception centres for the Jews.’
That had been his first encounter with Kammler.
His second came six weeks later, towards the middle of October. He had not wanted to go back to Nordhausen. ‘Must I?’ he complained to von Braun. ‘There is so much to be done here.’ After the death of Dr Thiel, he had taken over most of his responsibilities in the propulsion department, where they were still trying to solve the problems with the turbo pump steam generator system that had driven the excitable Thiel to the edge of a nervous breakdown.
‘You have to come,’ von Braun told him. ‘We have to get the rocket ready for mass production.’
Once again von Braun flew the plane himself, and this time as they descended towards the airfield he took them directly over the Kohnstein hill. Amid the dark green forests of pine, the abandoned gypsum quarries stood out like vivid white scar tissue. In the flat area to the south-west of the hill a big prison camp was under construction. Graf stared down at it uneasily. None of the barrack blocks had roofs, he noticed. If Kammler had brought in all these thousands of foreign labourers, where were they housed?
The answer was obvious as soon as they drove into Tunnel B. They lived underground, along the walls of the cross-tunnels, in tiers of rickety wooden bunk beds stacked four high like rabbit hutches. Half-barrels with wooden planks laid across the rim served as latrines. In some of the hutches men lay prone, skeletal; one with his eyes wide open was plainly dead. The stench of it. And the noise of it – the rumble of cement mixers, the ring of pickaxes, the muffled boom of explosions as further tunnels were excavated, the roar of the generators, the clank of railway trucks moving up and down the line, the barking of the guard dogs, the shouts of the SS overseers. And the sight of it, wherever one looked in the eerie dim yellow light: the moving sea of striped uniforms, an undifferentiated mass unless one made an effort to fix one’s eyes on one of