I got out of the first maze in twenty-seven minutes, and I am sure I got full marks. I have had a quick look at your second maze and I am sure that given time, I can find my way out of that one as well. However right now I don’t have time, I have to go and teach a class. From my knowledge of my colleagues, Xie Xingguo, Zhang Xin and Wu Guping have solved your first equation, but only Xie and Wu will have solved the second one; Zhang Xin will have handed in a blank paper. Oh, yeah, and I am pleased to make your acquaintance …

I am quite sure that at that moment my eyes were wide open with surprise, because she was absolutely correct: the only people who had solved both equations were Xie Xingguo and Wu Guping! I couldn’t help thinking about what she had said, and I seemed to hear Anderov’s voice in my ear: ‘Most ciphers are decrypted accidentally, and most great cryptographers are also discovered accidentally …’

Really, I could hardly believe it, but she had solved the first equation in the time it took me to smoke two cigarettes. Amazing! I was so excited I couldn’t sit still, and I kept going to the window, hoping that she would soon be on her way back from class. The umpteenth time that I looked out of the window I caught sight of her walking along carrying a bundle of mimeographed teaching materials, looking for all the world like a princess, her shoulders squared and her back straight. I was so excited to see her. All of a sudden she raised her head and looked straight at me, as if she had sensed something. When our gazes crossed, she seemed both surprised and pleased, and she casually blew me a kiss.

I really don’t know how to describe her. What can I say? I made up my mind that whatever personal problems she had, provided there were no political problems, I could make allowances. The minute she solved the first problem so easily, I had no hesitation in putting her name on the list of candidates. I really hoped that she would solve the second equation as soon as possible. It was almost midday, so I decided to get a room at the hostel for her, and demanded that she give me an answer by two o’clock.

‘No,’ she said.

‘What do you mean, no? If you want to take the test you’re going to have to complete it according to my conditions.’

‘Right. Then you’re going to have to tell me what you want the person you are looking for to do.’

‘Don’t ask. If you’re selected, of course you’ll be told. Otherwise I will never tell you.’