After returning to Luoyang, Cao Shuang and his brothers were carefully guarded, and on 9 February 249, Cao Shuang was accused of plotting treason, after the palace eunuch, Zhang Dang (), who had himself been sent to the "tingyu", had testified that Cao Shuang and his associates were planning to seize the throne for themselves. Cao Shuang was arrested along with his brothers and his supporters, including He Yan, Ding Mi, Deng Yang, Bi Gui, Li Sheng, and Huan Fan. They were subsequently executed along with the rest of their families and relatives on the same day. Jiang Ji had attempted to persuade Sima Yi to spare Cao Shuang and his brothers in consideration of the meritorious service rendered by their father, Cao Zhen, but Sima Yi refused. Two of Cao Shuang's subordinates, Lu Zhi () and Yang Zong (), had been implicated in the plot and arrested as well, although Sima Yi pardoned them under the rationale that: "Each of them was serving his own master."