Cao Shuang
In the winter of 248, Cao Shuang's protégé, Li Sheng, was appointed as the Inspector of Jing Province by the Wei imperial court. Before he left Luoyang to assume office in Jing Province, Cao Shuang sent him to check on Sima Yi. Cao Shuang and his followers overjoyed when Li Sheng reported that Sima Yi was indeed ill and that he could not even hear what Li Sheng said. According to Li Sheng, Sima Yi misheard "Jing Province" as "Bing Province". Cao Shuang sensed that Sima Yi no longer posed a threat to him and started to lower his guard against the latter.