After Li Jue and Guo Si took control of Emperor Xian due to disagreement, Yang Feng and Dong Cheng escaped from Chang'an and arrived at Luoyang. Yang Biao, the lieutenant, advised Cao Cao that he had a strong army and could be summoned to the court to assist the royal family, so he sent an envoy to summon Cao Cao to the court. When Cao Cao heard that Emperor Xian had arrived in Luoyang, he was preparing to go to protect the Emperor to gain the public's expectation, when the messenger of the Son of Heaven arrived, Cao Cao was very happy and led his army to the court. When Cao Cao followed the Emperor, Li Jue Guo Si came after him and killed him.