His words confirmed her astonishing suspicions. ‘You know about the spying?’

He looked at her with an ironic smile. ‘I’m in charge of it.’

‘Good God!’

‘That’s why I had to drop the whole business of the murdered children. Moscow ordered me to. And they were right. If I’d lost my job at the Air Ministry I would have had no access to secret papers, nor to other people who could bring me secrets.’

She needed to sit down. She perched on the edge of the bed beside him. ‘Why didn’t you tell me?’

‘We work on the assumption that everyone talks under torture. Knowing nothing, you can’t betray others. Poor Lili was tortured, but she only knew Volodya, who’s back in Moscow now, and Heinrich, and she never knew Heinrich’s second name or anything else about him.’

Carla was chilled to the bone. Everyone talks under torture.

Werner finished: I’m sorry I’ve told you, but after seeing me like this you were on the point of guessing it all anyway.’

‘So I’ve completely misjudged you.’

‘Not your fault. I deliberately misled you.’

‘I feel a fool just the same. I’ve despised you for two years.’

‘All the while I was desperate to explain to you.’

She put her arm around him.

He took her other hand and kissed it. ‘Can you forgive me?’

She was not sure how she felt, but she did not want to reject him when he was so down, so she said: ‘Yes, of course.’

‘Poor Lili,’ he said. His voice fell to a whisper. ‘She had been so badly beaten, she could hardly walk to the guillotine. Yet she begged for life, right up to the end.’

‘How come you were there?’

‘I’ve befriended a Gestapo man, Inspector Thomas Macke. He took me.’

‘Macke? I remember him – he arrested my father.’ She vividly recalled a round-faced man with a small black moustache, and she experienced again her rage at the arrogant power Macke had to take her father away, and her grief when he died of the injuries he suffered at Macke’s hands.

‘I think he suspects me, and taking me to the execution was a test. Perhaps he thought I might lose my self-control and try to intervene. Anyway, I think I passed the test.’

‘But if you were arrested . . .’

Werner nodded. ‘Everyone talks under torture.’

‘And you know everything.’

‘Every agent, every code . . . The only thing I don’t know is where they broadcast from. I leave it up to them to pick the locations, and they don’t tell me.’

They held hands in silence. After a while, Carla said: ‘I came to give it to Frieda, but I might as well give it to you.’

‘Give what?’

‘The battle plan for Operation Zitadelle.’

Werner was electrified. ‘But I’ve been trying to put my hands on that for weeks! Where did you get it?’

‘From an officer on the General Staff. Perhaps I shouldn’t say his name.’