After seeing Ts'ai Mao and Chang Yun killed,the other generals came into the tent and demanded that Ts'ao Ts'ao explain why they were killed.Ts'ao began to think that he had fallen for a plot to sow distrust among his officers.Instead of admitting his mistake,Ts'ao Ts'ao explained that the two generals had been killed because they balked at carrying out his orders.Then Ts'ao Ts'ao appointed generals Mao Chieh and Yu Chin to be the new marshals of his navy.