Several days later,Ts'ai Mao's younger brothers Ts'ai He and Ts'ai Chung crossed the river with 500 soldiers to surrender to Chou Yu.When they saw Chou Yu,they knelt down and cried,"Our elder brother was killed by Ts'ao Ts'ao for no reason.We come to surrender to you in order to take revenge on Ts'ao Ts'ao."Chou Yu was glad to hear this and sent them to serve under his general Kan Ning.