‘All right. Meet me in the Parc de la Citadelle at four-twenty-five exactly. Make certain that no one follows you.’
Memling started to ask where in the park, but she turned quickly, slapped him hard, jumped to her feet cursing in French, and was gone. What the hell was that for? he wondered. Then he caught sight of one of the old men grinning slyly, and understood.
A thin spatter of rain drifted across the cobbled street, and he glanced at the sky apprehensively. He had no money to buy lunch at a food stall, but if he went back to his room to eat, the landlady would wonder when he went out again, and there would be a thousand questions to dodge. Cursing the Germans and Maria, he mounted the bicycle and turned into the boulevard Piercot, trying to ignore the rhythmic bumping against the end of his spine as the patched tyre revolved on the cobbled street.
The original citadel was designed and constructed in the seventeenth century by Prince-Bishop Maximilian Henry of Bavaria. With each succeeding war or threat of war, the fort was expanded and strengthened until by 1914 it was thought to impose an impenetrable barrier to German designs.
The Imperial German offensive was begun on 5 August 1914. On 7 August General Erich Ludendorff entered Liege, and that same day, under bombardment from Krupp’s sixteen-inch howitzers, nicknamed the Big Bertha, the citadel surrendered. It would not be the last time an impregnable static defence position was overrun by superior technology. In 1914 it had been accomplished with giant cannon; in 1940, by glider-borne parachute troops.
Memling entered the gracious city park that had been constructed on the grounds of the old citadel and wandered about idly, examining the overgrown ruins of the strongest in a chain of twelve forts once thought sufficient to defend the city below. Liege, Namur, Mons, Maastricht, ancient citadels in the most fought-over area in Europe. His stomach protested its emptiness, and he was shivering in the chill breeze and wet clothes.
‘You must be the Englishman?’ A hand fell on his shoulder and? squeezed. ‘No, no. Keep walking. Just greet me as an old friend you expected to meet. Your cover name is Pieter Diecker, I believe?’
The shock of the unexpected approach, of being called an Englishman, had almost unnerved Memling, and he faltered. The hand held tightly to his shoulder, and he tried to smile but failed, miserably.
‘Maria’s description was quite accurate. I had no trouble spotting you.’
Memling glanced at the man walking beside him. Rather tall and spare, he had a thin moustache and a three-day stubble of beard. His hair was concealed beneath an army garrison cap that had seen better days, and the uniform greatcoat that flapped about his knees was filthy and carelessly mended. He walked with a pronounced limp – which had probably kept him out of the camps where soldiers of the former regime were required to do a period of labour service. The armistice had been in effect for seven months now, and very few men had yet been released.
‘By the way, my name is Paul. I apologise if I startled you, but your reaction confirms your identity.’
Memling’s breathing had begun to return to normal. ‘And if…. it hadn’t…?’
The man shrugged. ‘We would have walked into those trees.’ He palmed a thin-bladed military fighting knife before sliding it away in the depths of the coat. Memling drew an even deeper breath.
‘Where can we go?’
Paul laughed at that. ‘Right here, my friend. I do not know you well enough for anyplace else. And we must hurry. The Gestapo and the SD vie with each other for my head.’
They found a bench on the edge of the bluff overlooking the city. Memling struggled to find an opening that would catch the attention of this self-assured man. He knew nothing about him other than that he had been an army officer. How to explain something as complicated as rockets in a few minutes’ time? he wondered.
He decided on a straightforward account. ‘The Germans are developing a powerful rocket which will have the capability of flying perhaps three hundred and fifty to four hundred and fifty kilometres,’ he began. ‘It will carry an explosive charge of up to twelve hundred kilograms. The motors for this rocket are being constructed down there.’ Memling pointed to the distant roof of the Manufacture d’Armes.
‘In the Royal Gun Factory?’ Paul asked in surprise. ‘A rocket? Like a fireworks rocket?’
Memling shook his head impatiently. ‘No. Nothing like that at all. This one will be all metal, perhaps thirty metres high, with a powerful motor in which a mixture of petrol or alcohol and liquid oxygen will be burned. It will be able to climb thirty or more kilometres into the stratosphere and continue on for up to four hundred and fifty kilometres.’ Memling became aware that he was speaking much too quickly and drew a breath, fighting to slow himself down.
‘If launched from anywhere along the Atlantic or North Sea coasts, it could fall anywhere in London. It could be fired north to devastate Stockholm or across the Mediterranean against Egypt or targets in the Middle East.’
Paul whistled softly. ‘How do you know all this?’
The question was logical and at least did not express the complete disbelief he had been expecting. He began to relax a bit. ‘I saw the motors.’
‘Just the motors?’
Memling nodded.
‘Tell me where and when.’
The cloud along the western horizon had broken, and reddish light rushed through to flood the distant hills. Below, the city, shrouded in a century of industrial grime, remained grey and dismal. Memling began by describing his chance meeting in 1938 with Wernher von Braun and Franz Bethwig, his subsequent flight from the train, and the encounter with von Braun three days before, which had led to his glimpse of the sealed area.
‘I studied mechanical engineering and was also a member of the British Interplanetary Society,’ he continued, noting that Paul did not smirk or grin at the name as so many others had. ‘Before the war I helped to develop several small rockets that used liquid fuels. I am quite familiar with some of the problems.’
Paul nodded. ‘I think I understand. Tell me about what you saw at the works.’
‘There was sufficient time for me to get a good look. It was a bell-shaped object one and half metres high and half that wide. The bottom flared into a bell muzzle as a rocket nozzle would do. Above the nozzle was a spherical container from which a series of pipes depended. The sphere was most certainly the combustion chamber.’
‘How can you be certain of the size?’
‘The soldiers were moving another one inside. It was on a standard factory cart which stands exactly thirty-six centimetres high on its wheels. I measured one. The rocket motor rose to the level of the soldier’s chin. When he stood upright, he was as tall as I am, which is one point eight metres exactly.’
‘You are very perceptive. Where did you obtain the performance characteristics?’
Memling cleared his throat. ‘An engineer must be a good observer. As for the specifications… I – I calculated them from the dimensions of the engine.’
Paul nodded for him to continue.
‘From the apparent diameter’ – Memling’s voice was feverish with the urgent need to make this man understand – ‘of the nozzle it is possible to estimate the width of the rocket. From the diameter of the combustion chamber it is possible to construct a series of estimates of specific thrust based on the fuels that might be employed. Given that, the rate of fuel and oxidiser use can be estimated, which suggests the amount of fuel that can be carried and thus the possible range. That, in turn, provides an estimate of the weight of explosive that can be carried. Military considerations would further limit the choice of weights; for instance, it would make no sense to shoot a fifty-kilogram payload a thousand kilometres or a six-thousand-kilogram payload ten kilometres.’