While the Han court was in chaos Dong Zhuo marched his 200,000 battlewise（富有战场经验的） Xiliang troops into the capital of Luoyang. He forces Liu Bian to quit the throne and made Liu Xie the Emperor Xian and himself the prime minister. As he rode roughshod over（欺凌） the emperor, manipulated power for personal ends, and had acted extremely cruelly, all ministers and generals wanted to get rid of him.

Cao Cao, a wise and resourceful army officer, had long wanted to kill Dong Zhuo. One day, he came to see Dong Zhuo with a borrowed blade. the latter was sitting in his bedroom, his brave step-son Lv Bu standing by his side. Inquiring why he had been late, Cao Cao said, "My horse was slow." Dong Zhuo, now it's your time to die. But fearful of resistance from the old but still strong Dong Zhuo, Cao Cao waited for the right moment. As Dong Zhuo was a very large man, a while of sitting tired him and he lay down facing inward. Taking the chance Cao Cao unsheathed（抽出鞘） the knife. It so happened that Dong saw his move in a mirror. He looked back and asked Cao Cao what he was doing. Just then Lv Bu returned with a horse. The quick-witted Cao Cao made up a story, I chanced to secure a very unusual blade the knife to Dong Zhuo. Sure enough, the blade was extremely sharp, and about twenty some centimeters long. Delighted, Dong Zhuo told Cao Cao to have a look at the chosen horse. Outside, Cao Cao pleaded for a test ride. He then leaped onto the horse and sped away. "He must have come to murder me," said Dong Zhuo to Lv Bu. "I agree," the latter chorused. They sent soldiers to give chase, but by then, Cao Cao had fled out of the eastern gate.