After Cao Mao became emperor, he gradually established a circle around him – a number of officials who were unquestioned in their support of the Simas, but who might also have something to gain from allegiance to the emperor, including Sima Shi's cousin Sima Wang, Wang Shen (王沈), Pei Xiu and Zhong Hui. By doing this, he was hoping that he could minimise suspicion against him but at the same time gradually win their hearts. In 255, he made a failed attempt to capture power back – when Sima Shi died while at Xuchang, Sima Zhao was at Xuchang as well. Cao Mao issued an edict which, under the rationale that Sima Shi had just defeated Guanqiu Jian and Wen Qin's rebellion and that the southeastern border was still not complete pacified, ordered Sima Zhao to remain at Xuchang and that Sima Shi's assistant Fu Gu (傅嘏) return to the capital Luoyang with the main troops. Under Fu Gu and Zhong Hui's advice, however, Sima Zhao returned to Luoyang anyway against edict, and was able to maintain control of the government. Indeed, from that point on, he would not let Cao Mao or Empress Dowager Guo to be out of his control, and when Zhuge Dan made a failed rebellion in 257, believing that Sima Zhao would soon usurp the throne, Sima Zhao would insist on the emperor and the empress dowager accompanying him on the campaign against Zhuge Dan.