Today we are out in the countryside near Suzhou, amid lakes and rice fields, to talk to Mr Gu, one of the last people in the area who can be bothered to raise silkworms. There’s enough time in a year to raise five generations, but there simply isn’t enough demand for his silk anymore, so he’s dropped it to just one.

The farmhouse is grotty and ramshackle, all clucking chickens, yappy dogs and mangy cats, although when we send our drone over the top of the mulberry trees, there is a fantastic vista of fairytale Chinese Lakeland.

Indoors, Mr Gu takes a handful of silk cocoons and throws them into boiling water. Before long, they start to unravel, and he teases out a few strands and begins winding. Then he lets me take over: each cocoon is wound with 1.4 kilometres of thread, in a single strand. They look like spider silk, but easily take the punishment of being dragged out of boiling water and wound on a bobbin. Mr Gu says he boils 20,000 cocoons a year, which would make a strand of thread long enough to go around the world.

He has been a little spooked by the crew showing up “with a foreigner” – in fact, most of the crew are foreigners from Singapore, of course, but he means me. This has led him to call the local propaganda office, who have in turn sent a flunky to lurk around telling us that we should be filming the nice bridge in Nanxun. He’s getting on my nerves, not the least because he’s one of those Chinese who talk about me in the third person, as in “does he take sugar?” even though he has been told twice that I am a visiting professor in a Chinese university.

The director and I argue over another piece to camera – a one-minute monologue about changing conditions in the silk trade that I need to say eleven times, without putting a word wrong, while wandering through a grove of mulberry trees. Did Jili silk win a gold medal or a gold award at the Great Exhibition? What year was it in? Should we just say “19th century”, or will that only confuse people?

An interviewee can say anything they like on camera — in a phenomenological sense, we are interested in what they believe to be true. But a National Geographic presenter has to be academically robust, which means anything I say has to be backable by two printed sources — not something I read on the internet, something I can point to in a book if it is queried by Standards and Practises four months later. This isn’t really a problem if you’re in a library, but i’s a huge deal if you are standing in a field somewhere outside Shanghai, and asked to come up with a sixty-second speech out of thin air. My ability to say things like “I reckon we’ll find a paragraph on this in Hyde (1984)” is one of the things that got me this job.

We do get a moment with the nice bridge in Nanxun, an O-shaped arch over the canal, high enough to allow barges loaded with raw silk to pass through on their way to the south and the silk-weaving cities that would make it all into textiles. I must gabble a piece to camera against the failing light, while a dozen twats assemble nearby to peer through the viewfinder and/or talk loudly to their mates about what might be going on, when what is clearly going on is that I am trying to record a piece to camera. We get it on the fourth take, with the sun setting, and the director makes me run around the canal bank and up to the bridge so I can walk across it. To get there, I have to parkour across a building site and, at one point, grip the window ledge on a restaurant, pretending to be nonchalant as a bunch of surprised diners stare back at me.

Jonathan Clements is the author of The Emperor’s Feast: A History of China in Twelve Meals. These events featured in Route Awakening S02E04 (2016).