After Cao Cao died, his son Cao Pi succeeded Cao Cao. But Cao Pi's time in office was not long. After Cao Pi's death, Cao Pi's son Cao Rui became the throne. Cao Rui inherited Cao Cao's suspicion, but at the same time he was very eager to expand his territory and establish his own achievements. Cao Rui recruited Sima Yi back as a minister of the auxiliary country
At this time, Zhuge Liang launched the Northern Expedition, Cao Rui, and appointed Sima Yi to fight. After all, it seems that only Sima Yi is sure to defeat Zhuge Liang under Cao Rui's men. After receiving the appointment, Sima Yi went to the battlefield to start a game with Zhuge Liang. In fact, he and Zhuge Liang knew each other very well, but the two did not really meet each other. During this Northern Expedition, Zhuge Liang finally died of illness due to overwork. Sima Yi also realized that once Zhuge Liang died, his name might not be guaranteed. At this juncture, Cao Rui passed away and Cao Fang succeeded to the throne. Although Sima Yi was also ruthlessly attacked, Sima Yi finally chose to endure and survived. While they were relaxing in their seats, Sima Yi staged a coup and seized power.