He waited as Fyodorov sorted himself out. He noticed that the younger man held his coffee cup with both hands, and he remembered the days when he too would shake in the presence of such a senior officer. He didn’t think he came across as that harsh.

‘I hear very good reports about you, Leonid.’

‘Thank you, sir. It is an honour to serve the Soviet Union and to—’

Gurevich held up his hand to stop him. ‘I’m sure. There is an urgent matter that needs to be dealt with. You remember Willi Kühn?’

‘You mean Paul Hoffman’s contact?’

‘That’s him, the schoolteacher – former KPD member. I need him to do something for us, but I’m not sure how far we can trust him.’

Gurevich swivelled his chair round, and when he’d completed a full circle to face Fyodorov once more, he lifted his feet onto the desk and closed his eyes in thought.

‘Let me put this another way: if we were to approach Kühn, how do you think he’d react?’

‘He’s not the trusting type, sir.’

‘What’s Hoffman up to these days?’

‘Since the Volkspolizei was formed in October, he’s become a very effective officer in it, sir: I understand he is even trusted to investigate political crimes.’

‘So we could use him to approach Kühn?’

‘That would be a better approach, sir.’

‘I thought so. Very good, get Hoffman here now.’

An hour later, Paul Hoffman swaggered into Gurevich’s office without any of the nervousness shown by Fyodorov.

‘I want you to bring Willi Kühn here, Hoffman.’

‘When, sir?’

‘Ideally, an hour ago, but I’ll settle for some time tonight.’

Hoffman coughed and looked less confident now. ‘There is a slight problem with that, sir.’

Gurevich looked up in the manner of a man who had enough problems already. ‘Go on.’

‘He’s in Wedding, sir, in the western part of the city. I think that’s in the French sector.’

‘In that case, I’ll allow you two hours to bring him here.’

The war had been over for more than seven months, but that didn’t stop Willi Kühn breaking out in a cold sweat and his heart missing a beat or two when he heard knocking on his door so late at night.

At least he was alone. His daughter was working as a nurse at the French hospital, and his son-in-law was in a Soviet prisoner-of-war camp, where frankly Kühn hoped he would remain. Through the frosted glass he saw the shadows of two still figures.

‘Who is it?’

‘You don’t need to sound so worried, Willi. It’s me, Paul – Paul Hoffman.’

Kühn undid the chain. Hoffman’s face was just inches from his. He couldn’t make out the slightly shorter figure standing behind him.

‘What is it – am I in trouble?’

‘You will be if you don’t let us in,’ said the other figure. It spoke with a Russian accent. ‘It’s fucking cold out here.’

The three of them stood in the doorway, the light from the lounge spilling into the hall. Kühn peered at the Russian, trying to work out whether he recognised him. Fyodorov held a card in front of him and said he was NKVD.