‘I took her words deep into my heart and worked even harder than she demanded. I was never given the opportunity to meet any men except the servants, my tutors and teachers, so I had never known how beautiful I was, or that most men would find me irresistible.’ She broke off and shook her head ruefully. ‘Oh dear. Please forgive me, Badger. That sounds terribly immodest.’

‘No. It’s the simple truth. You’re beautiful beyond the telling of it. Please go on, Eva.’

‘Beauty and ugliness are random occurrences. The difference is that beauty fades and becomes another form of ugliness. I place no value on mine, but others did. It was one of the three reasons why they chose me. The second was my intelligence.’

‘What was the third?’

‘I had suffered a terrible wrong, and I was eager for retribution.’

‘I find this fascinating in a dreadfully sinister way. My skin is beginning to creep.’

‘For my nineteenth birthday the dressmaker made me a magnificent ballgown. Mrs Ryan stood beside me as I tried it on for the first time. Together we looked at my reflection in the full-length mirror.

She said, “You’re very beautiful, Eva. You’ve become everything we hoped you might be.” There was something sad and regretful in the way she said it. I thought little of it at the time because, of course, I had no idea what they were planning. Then she smiled and the sadness vanished. “Tomorrow night I’m holding a birthday party for you,” she told me.’ Eva laughed. ‘It was a very strange birthday party. Mrs Ryan and I went in a cab to a house in Whitehall, one of those magnificent government buildings. Four men were waiting for us. I had imagined that there would be dozens of young people, but there were just these four old men – the youngest was at least forty. Three were dressed in gorgeous military uniform. They must have been very senior officers for they wore glittering decorations, stars and medals. The fourth was thin and severe-looking. Mrs Ryan introduced him as Mr Brown. He was the only civilian in the group. He wore a black frock coat and a high collar.

‘We sat down to dinner at a round table in the centre of a large room, with massive chandeliers suspended from the ceiling. The panelled walls were hung with huge canvases of battle scenes – I remember one was a painting of Nelson dying on the deck of the Victory at Trafalgar, and another was of Wellington and his officers at Quatre Bras, watching the charge of Napoleon’s hussars. A band was playing in the gallery and, one after another, the officers danced with me. While they did so, they questioned me as though I were in the dock.

‘I cannot remember what we ate because I was so nervous that I lost all appetite. A servant poured champagne into my glass, but Mrs Ryan had warned me and I didn’t touch it. At the end of the meal all four men conferred in low tones that I couldn’t follow, then seemed to come to some agreement, for they nodded and looked extremely pleased with themselves. The evening ended with a speech from Mr Brown about duty and sacrifice. That was the end of my birthday party.

‘Two days later I met Mr Brown again, this time in less salubrious circumstances. We were in a musty office, filled with files of old papers in another part of Whitehall. He was kind and avuncular. He told me I was privileged to have been selected for a task of the utmost delicacy, which was vital to the interests and security of our beloved Britain. The stormclouds of war were gathering over the continent, he said, and soon the nation would be engulfed in flames. I couldn’t understand what this had to do with me – and all his rhetoric had a stultifying effect upon me until he mentioned the name of Otto von Meerbach. My attention was immediately riveted. He suggested that I was in a position to perform a memorable service for King and empire, and at the same time find retribution for the terrible wrongs my father and I had suffered at the hands of Graf Otto. All I had to do was induce him to tell me information that would be vital to Britain’s military interests.’

She laughed again but this time with genuine amusement. ‘Can you imagine, Badger? I was such a naïve and innocent little ninny that I hadn’t the faintest idea how I was supposed to make him tell me his secrets. I asked Mr Brown outright, and he looked mysterious and exchanged a glance with Mrs Ryan. “If you agree to do as we ask you will be taught,” he said.

‘As I recall, my exact words to him were “Of course I will. I just want to know how.” ’ She broke off, sat upright and looked solemnly into Leon’s face with the violet eyes he adored. ‘Nearly a year after I made that contract with the devil they deemed I was perfect in the role they had chosen for me. I learned everything there was to know about Graf Otto except, of course, the secrets I was to wheedle out of him. By then I knew that he was estranged from his wife of ten years, but as both he and she were good Catholics they were unable to divorce. There would be no question of my being coerced into marrying him once he had fallen under my fatal spell.’ She laughed without humour at this piece of hyperbole. ‘Mr Brown and Mrs Ryan placed me in the way of Graf Otto von Meerbach. It was arranged through one of the military attachés at the British Embassy in Berlin that I should be invited to his hunting lodge at Wieskirche. I had been taught my duty and I did it,’ she said flatly but, like a drop of dew on the petal of a violet, a single tear clung to her bottom eyelashes. ‘I was a virgin when I met Otto von Meerbach, and in mind and spirit I still was, until yesterday. My darling Badger, I don’t want to go into any more detail, and even if I did you would not want to hear it.’

They were silent for a while, then Eva could contain herself no longer. ‘Now that you know about me, do you despise me?’

Her voice was muted and her expression stricken. He reached out to her with both hands and cupped her face, gazing into her eyes so that she could see the truth of what he was about to tell her. ‘Nothing you have done, or ever will do, could make me despise you. You have let me into your soul and I have found only goodness and beauty there. You must remember also that when you look at me you are not looking at a saint. It was you who told me we are both soldiers. I have killed men in the name of duty and, like you, I have done many other things that I’m ashamed of. None of that matters. All that matters is that we are together now and we love each other.’ With his thumb he gently wiped away the tear.

At last she smiled. ‘You’re right. We love each other and we have each other. That is all that matters.’

The funeral procession stretched the full length of Unter den Linden. As the head of it reached the Brandenburg Palace the tail was out of sight at the far end of the boulevard. It was a wet, grey day, and the mourners lined both sides of the road, ten persons deep, under the drizzle. They were silent, except for the women’s weeping. A single drummer tapped out the Death March. A full squadron of cavalry led the procession: the hoofs of their horses clattered on the paving, and the pale light reflected dully from the blades of the drawn sabres. Eva stood in the front rank of mourners. She wore full-length black leather gloves, and a hat with black ostrich feathers on the crown. A black veil covered her eyes and the top half of her face.

Kaiser Wilhelm II rode his black charger ahead of the gun carriage that bore the coffin. He wore a shining spiked helmet with a golden chain chinstrap, and his black cloak was flared back from his shoulders over the rump of his mount. His expression was fiercely tragic. A team of magnificent black horses drew the gun carriage. The coffin upon it was enormous and made of transparent crystal so that Otto von Meerbach’s corpse was clearly visible to the mourners. He was dressed in the costume of a Roman emperor with a crown of laurel leaves on his head. In each of his great hairy fists he held an assegai, the blades crossed over his chest. Incongruously a Cuban cigar was clamped between his teeth.