The Róża I’d known at Ravensbrück had been a live wire of defiance and daring and desperate hope, the girl who taught me to curse like a sailor in five languages, who’d wisecracked instead of sobbed when she was told she was going to be executed the next day. Something was different. She seemed like a person who has been on a tear for a week and now has sobered up again.

The Grand Hotel in Nuremberg was crawling with reporters and soldiers, but not with young curvy porcelain-complexioned girls, or even tall angular ones. In fact there weren’t very many women there at all, because the US military had a half-hearted rule about not letting spouses come along, though some of the judges’ wives were there helping out. It wasn’t exactly like having French strangers grabbing kisses from any pretty girl on VE Day, but Róża and I caused heads to turn. People smiled and nodded politely and held open doors and grabbed Róża’s bag. People ushered us into the dining room, and though my meals were included in my board, I’d have never had to pay for them even if they weren’t, because people kept offering to buy us drinks and coffee and cigarettes.

There was a buffet. I carried both our plates so Róża could walk, one hand gripping her cane and the other pointing to what she wanted. We’d hardly said anything to each other since we got out of the car, though we’d smiled and thanked our entourage of helpful suited and uniformed men. But when we sat down across from each other at the little table over steaming plates of bratwurst sausages and potatoes, and another plate piled with a mountain of gingerbread Lebkuchen which Róża had collected without my noticing, we both suddenly started to laugh.

‘I eat by myself most nights and everything is still rationed in Britain,’ I said. ‘I have one room and no kitchen, just the coal fire and a gas burner. Cheese on toast and bouillon cubes.’

‘I live in a boarding house. I have meals cooked for me!’ Róża said. ‘As good as this, most of the time, but still – here we are! You and me in Germany, eating like kings!’ She paused, and challenged in a low voice, ‘Bless this food, Rose.’

This was more like the Róża I knew – everything she said heavy with hidden meaning. Lisette had always said a brief grace over our thin prison soup.

I sat up straight and sang a grace from Girl Scout camp. Not loud, but I sang.

‘Evening is come, the board is spread –

Thanks be to God, who gives us bread.

Praise God for bread!’

There was delighted laughter and a scattering of applause from the nearest tables around us. Róża ducked her head demurely, one hand shielding her face beneath the short, shining caramel waves of her permed hair, as though I’d embarrassed her.

‘You never taught us that one!’ she accused.

‘I forgot about it,’ I admitted. ‘I don’t think I ever felt thankful enough to sing that one. I never really felt thankful to get food there – just relieved.’

‘We are both ungrateful wretches,’ Róża said. ‘But praise God for bread anyway. Praise God for gingerbread!’

It felt so strange to eat with her – to eat a real meal together. We had slept pressed against each other like sardines for six months. We had stood naked in the snow side by side for two hours because one of the female guards had lost a watch or something, and they made our entire barrack line up outside and take all our clothes off so they could hunt for it. But we’d never sat at a table together and eaten a decent meal, not even after we got out. It made us both self-conscious.

‘You’re making me think I have to stuff it in before you take it away from me,’ Róża accused.

‘I know.’ And of course we’d never stolen food from each other, ever, which made the sensation of covetous greed very weird. We’d both been reasonably well-fed for the past year and a half and now we were in a restaurant in a fancy hotel. It had never occurred to me that simply being with a fellow prisoner would make me feel like I was still in prison.

We asked the hotel reception to fix it so we could share a room, which they were happy to do, because it freed up another room for the overflowing reporters and trial observers. When we got undressed for bed, Róża proudly showed off to me her Exhibit A legs.

‘I broke my right leg in the refugee centre in Belgium. This is the leg they took the bone samples from. It held for two and a half years in their camp and then it broke, just like that, a week after I got out. I wasn’t even doing anything – just carrying your soup across the gym hall for you.’

I realised, suddenly, the notable difference about her – she’d stopped swearing.

She peeled her thick wool hose down to her ankles. ‘See? Here, in my shin. The new scar is where they operated on it in Sweden. I have a steel rod in there now, holding everything together. I couldn’t stand up for four months!’

I took a deep breath. ‘I don’t know how I lost you, Róża.’

‘Oh, well I do.’ She flung her hose on a chair. ‘You were crazy about that reporter. You forgot us the second you laid eyes on him.’

‘I wanted to tell him all your names! I wanted to tell him about the Rabbits, about the experiments! You spent six months drilling everybody’s names into my head – Karolina and Elodie got dragged off to be gassed yelling that we should tell the world about it, that’s what Irina told me, and Bob was the first reporter I ran into! It was like he’d dropped out of the sky. And then I wasn’t brave enough to tell him anything.’

Róża laughed, not the old raucous cackle, but a soft, regretful sigh of a laugh. The ghost of a laugh. ‘That was us dropping out of the sky, not him. Remember? We’re the ones who crash-landed.’

‘I told the American Embassy your names,’ I said defensively.

We turned out the lights. It was a little room with twin beds. We lay in the dark wide awake with the weight of where we were and what lay ahead of us pressing on us.

‘Rose?’ she said softly.

‘Yeah?’ I answered.

‘It is just as strange to know you are there, and to be warm and comfortable, as it is to eat with you.’

‘It really is.’

‘Tell me “The Subtle Briar” again,’ she asked.

She knew I would still know it by heart.

I whispered to her in the dark.

‘When you cut down the hybrid rose,

its blackened stump below the graft

spreads furtive fingers in the dirt.

It claws at life, weaving a raft

of suckering roots to pierce the earth.

The first thin shoot is fierce and green,

a pliant whip of furious briar

splitting the soil, gulping the light.

You hack it down. It skulks between

the flagstones of the garden path

to nurse a hungry spur in shade

against the porch. With iron spade

you dig and drag it from the gravel

and toss it living on the fire.

‘It claws up towards the light again

hidden from view, avoiding battle

beyond the fence. Unnoticed, then,

unloved, unfed, it clings and grows

in the wild hedge. The subtle briar

armours itself with desperate thorns

and stubborn leaves – and struggling higher,

unquenchable, it now adorns

itself with blossom, till the stalk

is crowned with beauty, papery white

fine petals thin as chips of chalk

or shaven bone, drinking the light.

‘Izabela, Aniela, Alicia, Eugenia,

Stefania, Rozalia, Pelagia, Irena,

Alfreda, Apolonia, Janina, Leonarda,

Czeslava, Stanislava, Vladyslava, Barbara,

Veronika, Vaclava, Bogumila, Anna,

Genovefa, Helena, Jadviga, Joanna,

Kazimiera, Ursula, Vojcziecha, Maria,

Wanda, Leokadia, Krystyna, Zofia.

‘When you cut down the hybrid rose

to cull and plough its tender bed,

trust there is life beneath your blade:

the suckering briar below the graft,

the wildflower stock of strength and thorn

whose subtle roots are never dead.’

Róża gave a long sigh. Then she whispered, ‘Rose, I really miss you.’

Róża spent most of Sunday telling her story to Dr Leo Alexander – we had supper with him that night afterwards, before the other Ravensbrück witnesses arrived. Everyone I met who was involved in the trial was friendly and straightforward, as though we were at a conference. This was not quite what I was expecting, but I think it is a result of everything being pulled together at the last minute. And although I wasn’t one of Dr Alexander’s witnesses he was interested in me, because I am a writer and a medical student, which is a less advanced version of what he is.

Róża told him at supper, ‘Rose could be a witness here. She has scars too.’

He looked at me with sudden intense interest. ‘You do? An American witness?’

I shook my head violently. ‘I wasn’t operated on. I was just thrashed because I wouldn’t work. So was everybody who didn’t work, or who did anything else they didn’t like. We’re a dime a dozen and nothing to do with a trial for medical staff.’

‘I hate to say it, but you’re right,’ Alexander agreed. ‘I’ll admit I’ve already rejected several so-called witnesses exactly like you.’ He turned his mild, smart gaze back to Róża. ‘You will likely have heard of the concept of genocide, a term coined by your countryman Raphael Lemkin, which the IMT used as a basis for their charges against the Nazi leaders? We are using a parallel concept in this trial: thanatology, the science of producing death. These men are being charged with murder. The charge is that their experimentation was designed to discover not how to heal, but ways to kill. Simply put, you’re a survivor of attempted murder. A punitive lashing, however ugly the scars may be, is, unfortunately, irrelevant.’

‘I couldn’t show off my scars anyway!’ I protested, taking refuge in being ridiculous to hide my cowardice. ‘What would I do, step on to the witness stand in a bathing suit? A two-piece!’

‘It would be sensational,’ Róża exclaimed.

‘No one would notice any scars!’ Dr Alexander teased.

What a very weird dinner conversation.

The other Rabbits arrived. They were all as unrecognisable as Róża – well-fed, well-dressed, wearing their hair fashionably styled beneath new hats, smiling for the flashing press cameras at the train station. We hugged and kissed as if we were all long-lost family: Vladyslava, tall Maria, Jadviga, and little Maria who’d had to stay in the Revier for a year and a half. I hadn’t known any of them very well at Ravensbrück, but I knew their names. I’d hidden with Vladyslava and Jadviga in a pit dug beneath our washroom for two days. They’d hidden there with Róża for a week.

We were all on the bus to the Palace of Justice at 8.30 the next morning and stayed there till 6 p.m., and I didn’t see much of anybody that day. I got asked, ‘Can you type?’ and I said yes, and suddenly I was part of the team landed with the tortuous job of organising Dr Alexander’s notes as fast as he could hand us paper. I was set up in an office with the Chief Prosecutor’s wife, who was also working there, because I wasn’t allowed in the interview room with the Ravensbrück witnesses. Róża ran piles of paper back and forth between me and the rest of them, since she’d already been interviewed. I spent the first three days of that week in unwaged labour, gaining a little understanding of the trial and a lot more understanding than I’d ever wanted to know about the hideous things that had actually been done to Róża and the women I’d been imprisoned with.