It had taken six successive applications of peroxide to get Zhou Danrui’s hair to the desired shade of platinum blond.

The hairdresser and her assistant were exhausted. They had been on their feet, wrapping foil around her hair since 6am. It was nearly midnight now.

It was the assistant who first noticed the clumps of hair falling out. First one, then three, then five.

The hairdresser panicked. She wondered if she should mention this to her client. Probably best to keep mum about it- unless, of course, all the hair fell out.