During the Warring States period, Yan Sui, a minister from the State of Han, bore a deep grudge against the Prime Minister, Han Kui. He traveled to the State of Qi to find Nie Zheng, a dog butcher, seeking his help to assassinate Han Kui.

Nie Zheng, a man of great filial piety, initially declined as he was caring for his elderly mother. After his mother's death, Nie Zheng, deeply moved by Yan Sui's kindness and recognition, decided to repay his patron.

Armed with only a sword, he bravely infiltrated Han Kui's heavily guarded mansion and successfully assassinated him.

To prevent his identity from being discovered and to protect Yan Sui, Nie Zheng then committed a gruesome act of self-mutilation: he disemboweled himself, gouged out his own lungs and other organs, and disfigured his face, dying by suicide.