‘On her palm there was a smear of ink. On the scarf was the perfectly reversed imprint of an Ormaie Town Hall archive reference number. She’d written the number on her palm and tried to rub it out with the scarf when she was caught.

‘I spat on the scarf – as though in contempt of her, you understand? – and wadded it into a ball which I pressed back into her hand. But I rubbed the damp silk hard against her palm to blot the numbers out and closed her limp fingers round it, and all anyone ever found there was an ink-stained wad of cloth and no one ever asked her about it because she’d been filling out forms in the ration office just before she’d been caught, under the pretence of an errand for some made-up, elderly grandmother, and her fingers were covered with ink anyway.’

A flight of hopeful pigeons settled on the pavement around our feet. I am always so amazed at the way they flare and touch down – never a bounce or a prang, no one teaches them, they do it instinctively. Flying rats, but how beautifully they touch down.

‘How did you know what she wanted the number for?’ I asked at last.

‘She told me,’ Anna said.

‘No.’

‘She told me. At the end, after she’d finished. She was writing nonsense. I took hold of her pen to stop her, and she let go without a fight. She was tired. We’d worn her down. She looked up at me without hope – there’d be no more excuses now, no more reprieves. Ferber’s orders are all supposed to be cloaked in secrecy, but we both knew what he’d tell von Linden to do with her. Where they’d send her.’

Anna hit the back of her hand lightly against the railing for emphasis and demonstrated with her cigarette, holding it as though it were a pen.

‘In the palm of my own hand I wrote: 72 B4 CdB.’

She took a drag on the cigarette-pen, steadying herself.

‘She was the only one who could see it. Before the ink dried I closed my fingers and smeared the figures to an illegible blur. I picked up the pages she’d finished with and shuffled them together.

‘“That’s mine,” she said.

‘I knew she wasn’t talking about the pile of loose paper and card I was stacking. She was talking about the archive reference I’d written in my hand.

‘“What use is it to you?” I asked.

‘“No use,” she answered. “Not any more. But if I could …”

‘“What would you do with it?” I asked quietly. “What should I do with it?”

‘She narrowed her eyes like a cornered rat. “Set fire to it and blow this place to blazes. That would be the best thing to do with it.”

‘I held her stack of paper tight against my chest. Her instructions. She looked up at me with that challenging, accusing squint, you know?

‘“Anna the Avenging Angel,” she said, and then she laughed at me. She laughed. She said, “Well, it’s your problem now.”’

Anna threw her finished cigarette into the Poitou and lit another.

‘You should go home, Käthe,’ she said suddenly. ‘This English girl who sells motorbikes to Jews, this Maddie Brodatt – she’ll get you in trouble. You should go home to Alsace tomorrow, if you can, and let Maddie take her own chances.’

Get Käthe out of the picture before anything happens – that makes sense. It’ll be far safer for the Thibauts. Although I hate to go back into hiding. Tomorrow night I’ll be back in the barn loft, and it’s even colder there now than it was in October.

‘What about you?’ I asked.

‘I’m going back to Berlin. I applied for a transfer weeks ago, when we started interrogating her and that pathetic French kid. God.’ She shuddered, smoking furiously. ‘What shitty jobs they give me. Ravensbrück and Ormaie. At least when I used to requisition pharmaceuticals for Natzweiler I didn’t have to see what they did with them. Anyway I’m only here till Christmas now.’

‘You might be safer here. We’re bombing Berlin,’ I said. ‘We’ve been bombing it for nearly two weeks.’

‘Ja, I know,’ she said. ‘We listen to the BBC too. The Berlin Blitz. Well, we probably deserve it.’

‘I don’t think anyone deserves it really.’

She turned suddenly and gave me a hard look with those pale, glass-green eyes. ‘Except the Castle of Butchers, right?’

‘What do you think?’ I challenged angrily.

She shrugged and turned to head back to the Place des Hirondelles. She was out of time.

You know who she reminded me of – this is crazy. She reminded me of Eva Seiler.

Not of Julie normally, not really, but of Julie when she was angry. Made me think of her telling me the story of her mock interrogation under SOE training, in flat violation of the Official Secrets Act – the only time I can ever remember her chain-smoking the way Engel does, and swearing like a dockworker. ‘And six hours later I knew I couldn’t take it any more but I was just damned if I’d give in and say my name. So I pretended to faint and they all panicked and went running for a doctor. Bloody fucking bastards.’

Engel and I didn’t say much on the way back. She offered me another cigarette, and I had a moment of rebellion.

‘You never gave any to Julie.’

‘Never gave any to Julie!’ Engel gave an astonished bark of laughter. ‘I damn well gave her half my salary in cigarettes, greedy little Scottish savage! She nearly bankrupted me. Smoked her way through all five years of your pilot’s career!’

‘She never said! She never even hinted! Not once!’

‘What do you think would have happened to her,’ Engel said coolly, ‘if she had written this down? What would have happened to me?’

She held out the offered cigarette.

I took it.

We walked quietly for a while – two chums having a smoke together. Aye, right, miss.

‘How did you get Julie’s story?’ I asked suddenly.

‘Von Linden’s landlady did it for me. He had it at the desk in his room and while he was out she dropped the whole thing into a bag of linens to be washed. Told him she’d used it to light the kitchen fire – it does look like a pile of rubbish, all those damned recipe cards and the scratched-out forms.’

‘He believed that?’ I asked, astonished.

She shrugged. ‘No choice. She’ll suffer for it – milk and eggs cut to a limited supply strictly for her lodgers – the whole family under curfew in their own house, so they can’t sit up in the evening, bedtime straight after supper. She has to do all last night’s dishes in the morning before she makes breakfast for the guests. The children have all been strapped.’

‘Oh NO!’ I burst out.

‘They’ve got off lightly. The children could have been taken away. Or the woman sent to prison. But von Linden’s a bit soft on children.’

I’d left my bicycle in a street leading to the square. Just as I was taking hold of the handlebars Anna put her hand over mine. She pressed something heavy and cold and thin into my palm.

It is a key.

‘They asked me to bring some soap to scrub her up with when she had that interview,’ Anna said. ‘Something scented and pretty. I had some I’d got in America, you know how you save things sometimes, and I managed to make a print in it of the key for the service door at the back. This is a new one. I think you have everything you need now.’

I squeezed her hand fiercely.

‘Danke, Anna.’

‘Take care, Käthe.’

At that moment, as though she’d called him up by saying his name, Amadeus von Linden himself turned the corner of the street, walking towards the Place des Hirondelles.

‘Guten Tag, Fräulein Engel,’ he said cordially, and she dropped her cigarette and crushed it out with her foot and straightened her back and her coat collar all in a rush of practised panic. I dropped my cigarette too – seemed the right thing to do. She said something to him about me – she linked arms with me quickly, as though we were old chums, and I heard her say Käthe’s name, and the Thibauts’. Introducing me, probably. He held out his hand.

I stood there absolutely frozen for about five seconds.

‘Hauptsturmführer von Linden,’ Anna prompted gravely.

I put the key in my coat pocket with the architect’s drawings and my forged ID.

‘Hauptsturmführer von Linden,’ I repeated, and shook hands with him, smiling like a lunatic.

I’ve never had a ‘mortal enemy’. I’ve never known what it meant even, something out of Sherlock Holmes and Shakespeare. How can my whole being, my whole life up to this point, be matched to one man in deadly combat?

He stood gazing through me, distracted by his own colossal problems. It never occurred to him that I could tell him the secret coordinates of the Moon Squadron’s airfield, or give him the names of half a dozen Resistance operatives here in his own city, or that I was planning to send his entire administration up in flames in five days. It never occurred to him I was in every way his enemy, his opponent, I am everything he is battling against, I am British and Jewish, in the ATA I am a woman doing a man’s work at a man’s rate of pay, and my work is to deliver the aircraft that will destroy his regime. It never occurred to him that I knew he’d watched and made notes while my best friend sat tied to a chair in her underwear having holes burnt in her wrists and throat, that I knew he’d commanded it, that I knew that in spite of his own misgivings he’d followed orders like a coward and shipped her off to be used as an experimental lab rat until her heart collapsed – it never occurred to him that now he was looking at his master, at the one person in all the world who held his fate right between her palms – me, in patched hand-me-downs and untrimmed hair and idiot smile – and that my hatred for him is pure and black and unforgiving. And that I don’t believe in God, but if I did, if I did, it would be the God of Moses, angry and demanding and OUT FOR REVENGE, and

It doesn’t matter whether I feel sorry for him or not. It was Julie’s job and now it’s mine.

He said something polite to me, his drawn face neutral. I glanced at Anna, who nodded once.

‘Ja, mein Hauptsturmführer,’ I said through clenched teeth. Anna gave me a sharp kick in the ankle and leaped in to make an excuse on my behalf. I put my hand in my pocket and felt the crackle of thick paper 70 years old, and the new key weighing heavy in the seam of the threadbare woven wool.

They nodded to me and walked on together. Poor Anna.

I liked her very much.

Käthe’s gone back to Alsace and I’m waiting for the moon again – everything in place and we’ve had confirmation of a bomber fly-past planned for Sat. night – whether or not Op. Verity is successful they’re sending a Lysander for me, at the field I found, on Sunday or Monday – all of it weather permitting and of course assuming we can collect the Rosalie. Jolly difficult to sleep and when I do I just have nightmares about flying burning planes with faulty chokes, being forced to cut Julie’s throat with Etienne’s pocket knife, etc. If I wake up yelling three times a night there’s not much point in trying to hide. I am flying alone.