On the road home, I made sure to pass by a post office so that I could send a money-order for 100 yuan to Abing’s mother. I told Abing that this wasn’t my personal cash, but rather money belonging to Unit 701. Like me, they hoped that Abing would be able to quickly identify the remaining enemy frequencies. My telling him this had a particular purpose. I knew that Abing was a loving son and I knew he valued comradeship, so I knew it would make him give his all.

Once back in our mountain compound, I went to the archives and brought out eight large boxes of audio tapes – recordings made of the twelve missing radio stations before they went silent. I played them for Abing and told him, ‘Right now, your task is to listen to these audio tapes, over and over if necessary, but always carefully. What are you listening for? Well, don’t listen to how they broadcast – that is, don’t try to identify the special qualities of the radio frequency. Instead, listen to how the broadcasters “speak”; listen to their “voices”. I believe you should be able to make out how many people are actually “speaking”, and therefore you should be able to discern their individual characteristics.’

I thought that since we had determined that the only possible reason why we hadn’t been able to identify these twelve stations (at least twelve, perhaps more) was that they were using an entirely unknown radio model, then the only option left for us was to abandon our usual approach and attempt the unusual. If Abing was able to distinguish between the individual operators broadcasting on these stations, if he was able to identify their specific characteristics, then perhaps this could be a shortcut to finding them.

But that was easier said than done.