‘Under normal circumstances, yes. A tailor makes a garment for you, you give it to me, it doesn’t fit, so I take it back to the tailor and he’s happy to make the alterations. But Sivincy is not like the rest of us; her mind is dominated by hatred and revenge, and she cannot tolerate the slightest difference of opinion or criticism. To her, the relationship between America and Taiwan is not one of equals; it’s the relationship of a superpower and a Third World country – one is rich and the other poor, one is strong and the other weak. She made this dress for a princess to wear, but now it has fallen into the hands of a maid. If the maid asks her for alterations, is she likely to do them? I don’t think so.’

She looked at me in stunned silence and then suddenly got excited. ‘I know what you’re trying to say! The Taiwanese couldn’t get Sivincy to help them, so they tailored the cipher themselves. As a result the error rate increased beyond normal levels!’

I said yes, that seemed quite possible to me.

She was thrilled. ‘It’s only too likely. How come I didn’t think of that myself? And you … why didn’t you say something earlier? I could have got to work on the cipher itself long ago!’ She then rushed out without another word.

You know, I really wasn’t expecting that my idea, which anyone could have had, would make Huang Yiyi so happy. That very day she worked out a way to prove her theory, and then quickly found her way through all the residual problems, forcing her way out of the bottleneck that had been holding up our cryptographic work for so long.

That was the last big problem with RECOVERY: solving this structural issue allowed her to correct the cipher’s mathematical formulae.

You can probably imagine what happened next. Huang Yiyi basically moved into her office and shut herself in, working flat out without sleep and forgetting to eat. Sometimes when Comrade Zha hammered on the door shouting at her to come out and eat she paid no attention at all, and it was only after Zha knocked for ages that she would finally notice. One day I bumped into her in the corridor as she was leaving the lavatory, and her haggard appearance gave me a turn: she’d got a lot thinner, her eyes were bloodshot, her forehead deeply lined, her hair a bird’s nest! I wanted to say something to her, but she quickly shushed me. I knew she was worried I might break her train of thought.