‘I’m not getting into that thing,’ Volodya said. ‘I’ll go by train.’

‘As you wish.’

‘I’ll see you at the Adlon, but don’t acknowledge me.’

‘Of course.’

Half an hour later, Volodya saw Werner’s car carelessly parked in front of the hotel. This cavalier attitude of Werner’s seemed foolish to him, but now he wondered whether it was a necessary element of Werner’s courage. Perhaps Werner had to pretend to be carefree in order to take the appalling risks required to spy on the Nazis. If he acknowledged the danger he was in, maybe he would not be able to carry on.

The bar of the Adlon was full of fashionable women and well-dressed men, many in smartly tailored uniforms. Volodya spotted Werner right away, at a table with another man who was presumably Heinrich von Kessel. Passing close to them, Volodya heard Heinrich say argumentatively: ‘Buck Clayton is a much better trumpeter than Hot Lips Page.’ He squeezed in at the counter, ordered a beer, and discreetly studied the new potential spy.

Heinrich had pale skin and thick dark hair that was long by army standards. Although they were talking about the relatively unimportant topic of jazz, he seemed very intense, arguing with gestures and repeatedly running his fingers through his hair. He had a book stuffed into the pocket of his uniform tunic, and Volodya would have bet it contained poetry.

Volodya drank two beers slowly and pretended to read the Morgenpost from cover to cover. He tried not to get too keyed up about Heinrich. The man was thrillingly promising, but there was no guarantee he would co-operate.

Recruiting informers was the hardest part of Volodya’s work. Precautions were difficult to take because the target was not yet on side. The proposition often had to be made in inappropriate places, usually somewhere public. It was impossible to know how the target would react: he might be angry and shout his refusal, or be terrified and literally run away. But there was not much the recruiter could do to control the situation. At some point he just had to ask the simple, blunt question: ‘Do you want to be a spy?’

He thought about how to approach Heinrich. Religion was probably the key to his personality. Volodya recalled his boss, Lemitov, saying: ‘Lapsed Catholics make good agents. They reject the total authority of the Church only to accept the total authority of the Party.’ Heinrich might need to seek forgiveness for what he had done. But would he risk his life?

At last Werner paid the bill and the two men left. Volodya followed. Outside the hotel they parted company, Werner driving off with a squeal of tyres and Heinrich going on foot across the park. Volodya went after Heinrich.

Night was falling, but the sky was clear and he could see well. There were many people strolling in the warm evening air, most of them in couples. Volodya looked back repeatedly, to make sure no one had followed him or Heinrich from the Adlon. When he was satisfied he took a deep breath, steeled his nerve, and caught up with Heinrich.