Cao Zhang is brave and good at fighting, but he loves chess. Cao Pi's books are just what he likes. By the middle of the game, Cao Pi had been losing ground. At this time, he said to the maid waiting beside him, "Bring the dates." So, while playing chess, they ate black dates. On the surface, they are very affectionate. In fact, the vicious Cao Pi had poisoned some dates and secretly marked them. He chose the ones that were not poisoned. Poor Cao Zhang was kept in the dark. After a while, Cao Zhang felt top-heavy and his eyes were straight. Before he could say a word, he fell to the ground. Someone has informed the Queen Mother Bian, and when the Queen Mother Bian comes, she still failed to save Cao Zhang. The chessboard was finally covered with Cao Zhang's bright red blood. Back to the fief, Cao Zhi touched the scene and wrote a poem entitled "A White Horse for Wang Biao", expressing deep condolences for the death of Cao Zhang and protesting against Cao Pi's cruelty to his own flesh and blood. Objectively, it also exposed the cruelty of the ruling class in frying beans.