Sima Yi, to deceive Cao Shuang into…

Sima Yi, to deceive Cao Shuang into letting down his guard, had stopped all political activities in May 247 and later retired, and he goes further in pretending to be ill and senile.

In the winter of 248-249, Cao Shuang's protégé Li Sheng is named as the administrator of Jingzhou, and before he leaves for his position, Cao Shuang sends Li Sheng to check on Sima Yi.

Cao Shuang and his followers are overjoyed when Li reports that Sima Yi is indeed ill and dying, that he could not even hear clearly what Li Sheng had said.

Cao Shuang, sensing that Sima Yi no longer poses a threat to him, draws his attention away from Sima.

On January 6, 249, Cao Shuang and his brothers leave the capital to accompany the child emperor Cao Fang to pay respects to Cao Rui at his resting place at Gaoping Tomb, and they continue to stay out on a hunting expedition.

Sima Yi and his sons launch a coup d'état and seize control of the capital city by first closing all the city gates.

Sima then assigns his protégés to take over the positions held by Cao Shuang's brothers after taking the armory: Excellency over the Masses Gao Rou replaces Cao Shuang, and Imperial Herdsman Wang Guan replaces Cao Xi to command the imperial bodyguards.

Sima Yi goes to see the Empress Dowager, requesting her to give an order to arrest Cao Shuang and his brothers on charges of treason.

Huan Fan, an advisor of Cao Shuang, escapes with the seal signifying the power of Grand Commander and brings it to Cao Shuang.

Cao Shuang is in a dilemma, unsure whether to surrender his power or not.

Cao Shuang's family and loved ones are in Sima Yi's control, and Sima Yi promises that Cao Shuang will not be harmed, as Sima is only after Cao's power.

Eventually, Cao Shuang agrees to surrender and gives up his power.

On January 10, 249, Cao Shuang returns to Luoyang, the capital of Cao Wei, and his fate is sealed.

Once having gained power, Sima Yi has Cao Shuang and his brothers arrested on charges of treason, then has them executed.

Sima Yi refuses to take the position of Imperial Chancellor awarded to him, and remains as Grand Tutor.