Not in a month of Sundays had he expected to hear from the Englishman, but now here he was on Moselstrasse giving the correctly coded messages. Gertrud had told him to hurry: the man would be back soon.

Now he was waiting in the cellar of the building next to the potato stall, reflecting on how fortunate it was that he was in Frankfurt that morning. The ceiling had been destroyed, exposing the room to the rest of the building, but it had been patched up with boarding, and enough of the rubble had been swept away to accommodate an incongruous patch in the middle containing a rug and two dusty armchairs.

The Englishman was in a bit of a state when he climbed awkwardly into the cellar. He didn’t look well, for a start, and there was a fresh soup stain down the front of his coat. He was carrying a small suitcase and a briefcase, which he clutched tightly to his chest when he sat down.

He said nothing as he glanced around anxiously, his eyes narrowing to adjust to the dim light. He had clearly forgotten his instructions.

‘And you are…?’

He apologised profusely and said in quite reasonable German that his name was Michael and he was still interested in purchasing the painting of the kestrel.

Ulrich replied that that was no problem, that it was indeed still for sale but he would require the money first, and although the Englishman hesitated, he did open the briefcase, though with a degree of reluctance.

‘It should all be there, but I’m afraid it’s been rather messed up, what with one thing and another.’

Ulrich took the money out, not bothering to count it as he folded it into rolls, which he secured with string and placed in his rucksack, before handing the briefcase back to the Englishman. ‘Thank you.’

‘That’s it?’

‘That’s it.’

‘I don’t need the painting?’

‘An unnecessary touch.’

‘But what if I’m stopped again?’

Ulrich shrugged as if he didn’t really care. ‘I’m sure you’ll think of something to say. Tell me, what happened with the Americans?’

The Englishman told him it was nothing: they’d been concerned at the amount of US dollars and British money he was carrying but were satisfied with his explanation.

‘That’s all?’

‘That’s all. Perhaps I ought to leave now. I’m going to try and catch the train to Cologne.’

‘I heard you were also questioned by the British?’

‘Well, yes, after a fashion – but they must have been satisfied with my explanation too.’

‘What did you tell them about meeting me?’

‘I just told them I was buying a painting from a man at that market.’

‘Did you give any details about me or the painting?’

The Englishman hesitated for far too long and shifted awkwardly in the armchair.

‘I don’t believe I did, no.’

‘So how come they’ve been asking around IG Farben about Kestrel, and specifically about a man called Friedrich?’

The Englishman looked shocked. ‘I really have no idea.’