Stinnes fielded the questions artfully and let Slinger demonstrate his technical knowledge until he got on to signals procedures. This was something that Moscow had agreed he could disclose, so, quietly and conversationally, he went through the Embassy routines. He started with the day-to-day domestics and went on to a few KGB encoding styles. These were technical developments that Slinger was unlikely to be familiar with, and thus he was unlikely to know that they had already been superseded or were used only for mundane traffic.

Out of the corner of his eye he watched Rensselaer uncoil like a serpent disturbed by the approach of heavy footsteps. 'This is all new to me,' said Slinger repeatedly, his accent more pronounced as he filled sheets of paper with notes scribbled so fast and so excitedly that his pencil broke and he had to grab another and ask Stinnes to slow down.

The other members of the committee became enthusiastic too. Between eager questions from Slinger, one of the committee asked him why he hadn't disclosed these gems earlier. Stinnes didn't answer immediately. He looked at Bret Rensselaer and then looked away and took a long time lighting up a cheroot.

'Well?' said Bret finally. 'Let's hear it.'

'I did,' said Stinnes finally. 'I told you during the first days but I thought it must be stuff you knew already.'

Bret jumped up as if he was going to start shouting. They all looked at him. And then Bret realized that an argument with Stinnes in front of the committee was only going to make him look ridiculous. He sat down again and said, 'Carry on, Slinger. Let's get it down on paper.'

Stinnes inhaled on his cheroot and looked from one to the other like a social worker in the presence of a combative family. Then he started to give them even more material: Foreign Country routeings, Embassy signals room times and procedures and even Embassy contact lists.

It took about an hour, and included some long silences while Stinnes racked his brains, and a few little Stinnes jokes which – due to the tension in the room – everyone laughed at. By the end, the committee was intoxicated with success. Satisfaction flushed their faces and circulated through their veins like freshly sugared blood. And not the least of their triumph was the warm feeling they got from knowing that Bret Rensselaer, so cold and patrician, so efficient and patriotic, was going to get his rightful comeuppance.

As Stinnes left the room to be taken upstairs he looked at Bret Rensselaer. Neither man registered any change of facial expression and yet there was in that exchange of looks the recognition that a contest had been fought and won.

But Bret Rensselaer was not the sort of man who would lie down and play dead to oblige an enemy. Bret Rensselaer was an American: pragmatic, resourceful and without that capacity for long-term rancour that the European is born with. When Bret faced the wall of opposition which Moskvin and Stinnes had between them constructed brick by brick, he did something that neither of the Russians had provided for. Rensselaer went to Berlin and pleaded for the aid of Bernard Samson, a man he'd come to dislike, reasoning that Samson was even less conventional than he was, and certainly far more savage.

'What do we do now?' Bret asked. Stampeded by Stinnes and faced with the prospect of arrest, Bret ran. He was a fugitive and looked like one: frightened and dishevelled and lacking all that smooth Rensselaer confidence.

'What do we do?' echoed Samson. This was Bernard's town and both of them knew it. 'We scare the shit out of them, that's what we do.'

'How?'

'Suppose we tell them we are pulling out Stinnes's toenails one by one?'

Bret shivered. He wasn't in the mood for jokes. 'Be sensible. Bernard. They are holding your friend Volkmann over there. Can't you see what that means?'

'They won't touch Werner.'

'Why not?'

'Because they know that for anything they dream up to do to Werner I'll do it twice to Stinnes, and do it slowly.'

'Is that a risk worth taking?' asked Bret. 'I thought Volkmann was your closest friend.'

'What difference does that make?' asked Bernard.

Alarmed, Bret said, 'Don't get this one wrong, Bernard. There is too much riding on it.' Samson had always been a hard-nosed gambler, but was this escalating response the way to go? Or had Bernard gone mad?

'I know the way these people think, Bret. Moscow has an obsession about getting agents out of trouble. That is the Moscow law: KGB men ignore it at their peril.'

'So we offer to trade Stinnes for Werner Volkmann?'

'But not before letting them know that Stinnes is going to go through the wringer.'

'Jesus! I don't like it. Will Fiona be one of the people making the decision?' asked Bret.

Bernard looked at him, trying to see into his mind, but Bret's mind was not so easy to see into. 'I should think so,' said Bernard.

'Frau Samson,' said Moskvin with exaggerated courtesy and an unctuous smile. 'Have you prepared charges against this West German national Volkmann?'

'I am in the process of doing so,' Fiona Samson fielded the question. She'd learned a lot about Moskvin in the time she'd been working here. Some people thought Moskvin was a fool but they were wrong: Moskvin had a quick and cunning mind. He was pushy and gauche but he was not stupid. Neither was he clumsy, at least not in the physical sense. Every day he was in the basement: weight-lifting in the gym, swimming in the pool, shooting on the range or doing some other sort of physical exercise. He was no longer young, but still he had that overabundance of energy that is usually confined to childhood.

'Do you have another file on him, Comrade Colonel?' he asked sweetly.

Fiona was disconcerted by this question. She had created the Volkmann file that was open on her desk. 'No more than what you've seen already.'

'No more than this?' said Moskvin, and was able to make it into a very unfavourable pronouncement.

'I know…'she stopped.

'Yes? What do you know?'

'In the past he has worked for the SIS office in Berlin.'

Moskvin looked at her. 'Suppose Moscow wanted to see the file on Volkmann? Is this what we'd send?' He flipped the card cover of the file so that his fingernails made a click. It sounded empty.

'Yes,' said Fiona.

Moskvin looked at her and made no secret of the extent of his contempt. Intimidation was a part of his working method. By now she'd recognized him for what he really was. She'd known plenty of other men like Moskvin. She'd known them at Oxford: rowdy sportsmen, keenly aware of their physical strength, and relishing the latent violence that was within them.

'I know Volkmann,' she said. 'I've known him for years. Of course he works for SIS Berlin. SIS London too.'

'And yet you've done nothing about it?' Moskvin looked at her with contempt.

'Not yet,' said Fiona.

'Not yet,' he said. 'Well, now we'll do something, shall we?' He was patronizing her, smiling as tyrants do with small children. 'We'll talk to Volkmann… perhaps scare him a little.'

'How?'

'You might learn something, Frau Samson. He hasn't been told that he's being released in exchange for Major Stinnes. We must make him sweat.'

'Volkmann gets his money from doing business in our Republic. Without that he would be penniless. He might be persuaded to work for us.'

Moskvin eyed her. 'Why would he do that?'

'He's back and forth all the time. That's why he was so easy to pick up. Why shouldn't he tell us what happens over there?'

'You could do that?'

'I could try. You say he's being held in Babelsberg?'

'You'll need a car.'

'I'll drive myself.'

'Bring him back here. I'll want to see him too,' said Moskvin.

She smiled coldly at him. 'Of course, Colonel Moskvin. But if we frighten him too much he won't come back.'