The Wu sisters are in their seventies, and have a relatively posh house near the centre of the village, alongside their ramshackle dyeing studio. There, behind a door so low I practically have to limbo underneath it, they make Kam clothes by dipping cotton cloth into a mixture made from indigo leaves, collected from the riverside and soaked for three days to create a bluish soup. The clothes come out yellow, but oxidise almost immediately on contact with the air, turning a pale blue. The Wu sisters will dip and wash and dry and dip and wash and dry over and over for the next twenty days to get the right level of dark blue.

Other ingredients include cow skin, with hair still attached, which is boiled for gelatin, pig’s blood which can be used to form the red dye that turns the dark blue into black, and rice wine.

“You can drink it!” enthuses Wu Big Sister. “Go on, have a go! We already have!”

She titters playfully, and I realise that the Wu sisters have been knocking back some of their ingredients all morning. I join in, and then they start singing a song of Kam welcome, which apparently has to end with me downing a grubby Hello Kitty mug full of rice wine. They then reveal that nobody can leave their house until they, too, have downed a mug of wine, leaving the cameraman and the driver red-faced and somewhat the worse for wear.

The Wu Sisters, however, are ready for anything.

“Come on inside!” says Wu Little Sister. “We’re going to whack the cloth with the hammer to make it soft and shiny!” She proceeds to smack her cloth around with a mallet dangerously close to her fingers.

I try to leaven the shoot with comedy business, including a Jacques Tati masterpiece of idiocy as I attempt to get across the village square when it is carpeted with drying rice. I negotiate a maze of rice mats, and end up dangling from the side of a building and braining myself on a jutting joist. I also get to turn to camera with a straight face and say: “There’s nothing I enjoy more than a good pounding.”

Jonathan Clements is the author of A Brief History of China. These events featured in Route Awakening S03E02 (2017).