‘Why did you want to see me?’

She handed me a piece of paper. ‘My answer.’

Although she had said that she didn’t want to do it, in fact she had gone home and got on with it. I looked through the workings and found the solution, and she was absolutely correct. I was very pleased, but when I spoke it came out sounding strange. ‘Dr Huang.’

‘Please don’t call me that. Right now I am your student and you are examining me.’

‘So how do you think you have done?’

‘I have made no mistakes.’

‘Well, you are the one with a PhD …’

She stopped me again. ‘I have already told you not to call me Doctor. Do you know what I think about my PhD?’

‘What?’

‘During the day I have a PhD; at night I don’t.’

‘What do you mean?’

‘What do you think? PhDs are only human. At night, they’re out for fun the same as anyone else.’

As she spoke she started laughing really hard, and ended up bent over. As she bent, I unintentionally caught sight of her breasts again, bursting seductively out of her clothes. I thought to myself that Party Secretary Wang was absolutely correct: would it be suitable for me to take her away with me? The minute this idea flashed across my mind, I dismissed it. I decided that this was not a question of personal suitability, because only she could do the job.

When she had finished laughing, she asked me politely, ‘You said that you had been looking for me. What’s up?’

I answered just as politely, ‘I need to ask you a couple of questions, and I hope you will answer them truthfully.’

She looked at me coaxingly, and said, ‘Don’t make them too difficult.’

‘They aren’t difficult at all, but you must tell the truth.’

‘No problem. Ask away.’

‘Question number one. Have you ever done any cryptography before?’

‘Yes.’

‘Would you be willing to do that kind of work again?’

‘No.’

‘Why not?’

‘Because it really is the devil’s work!’

‘Do you know who I am?’

‘I guess you are with the security services, am I right?’

‘You are absolutely correct. Are you willing to join us?’

‘No. And to join a top-secret unit, definitely not.’

‘What is the problem with a top-secret unit?’

‘Is that the place for someone like me?’

‘What do you mean, someone like you?’

‘Independent, romantic, someone who hates having to go by the rules, someone who is happiest when free from ties.’

‘Then why on earth did you insist on taking the test?’ I was getting angry.