I went on to ask the cook a few questions. It was his first time being questioned by the police, so he was very nervous and kept nervously insisting that he had nothing to do with the murder.

According to him, Xiaoli was very self-conscious about her looks. She would always worry about her face looking too fat, her legs not being skinny enough or her hands looking too wrinkly. She would often spend a significant chunk of her money on beauty products.

But Xiaoli’s family was very poor. She had to work here part-time while she studied for the past two years. Once, the cook noticed that her face had become thinner and asked her what she had done. She proudly replied that she had found a ‘magic potion’—cheap Botox from the internet.

One vial of Botox sold online cost about two hundred yuan, while an injection at a plastic surgery clinic would cost thousands of yuan. Xiaoli was a medical student, so she could...