Almost making matters worse was the fact that the course was going really well. Our relationship with the students had never been better. Maybe it was the success of the hit that fired them up; whatever, a lot of jokes were flying about and morale was great. Sasha was all over the place in his desire to be helpful.

At lunchtime Anna and I went for a walk. I’d already had some food when she appeared at the back of the building, yet I offered her lunch – God knows what we would have given her if she’d accepted. But she said she’d had an apple, and otherwise didn’t intend to eat until the evening.

So it was that we strolled off down one of the tracks into the training area.

I think her intention was just to be friendly, and to thank us again for leading the raid; but gradually her talk turned to the present good relations between East and West, and the contrast with the bad old days of the Cold War, when the KGB was crazily suspicious and went to fantastic lengths to penetrate foreign embassies in Moscow.

‘You know what happened in the Japanese Embassy?’ she asked.

I shook my head.

‘It was an old merchant’s house, like your British Embassy. It still had fireplaces and chimneys. So the KGB decided that the way to penetrate it was by sending a man down a chimney to plant microphones. They found a very thin man, trained him to climb, and sent him off.’

She stopped, looking at me.

‘And what happened?’

‘Nothing! The man was never seen again. That was the end of him. Did he get stuck? Is he still there, perhaps? Did the Japanese catch him and feed him to their tame fish? Nobody knows. Of course the KGB couldn’t ask, so they never found out.’

I laughed and said, ‘When you worked in London, I suppose you were spying too?’

‘Naturally! All Russians abroad were spies then. We were running the Intourist office, of course, but every day we were sending in reports to the KGB.’

‘What about?’

‘Oh, prominent people who booked air tickets or tours, foreign visitors to London, economic activity in general . . . I’m sure most of the information was useless, but we thought we were tremendously important.’

‘But how did you get into spying in the first place?’

‘To see the world. Isn’t that what you say about your navy? “Join the navy and see the world”? That was it with the KGB, exactly. In those days, the only chance you had of getting out of the Soviet Union was by joining the Ministry of Foreign Affairs or the KGB. Those were the two best careers on offer.’

Several times during our chat I almost challenged her about the business of our lap-top. But I decided on balance that it was better not to stir things up.