 On 5 February 249, when Cao Shuang accompanied Cao Fang on a visit to the Gaoping Tombs, his co-regent Sima Yi took advantage of his absence to stage a "coup d'état" and seize control of all the armed forces in the imperial capital Luoyang.Lu Zhi (魯芝), a major under Cao Shuang, prepared to lead his men to fight their way out of Luoyang and regroup with Cao Shuang.When Lu Zhi asked Xin Chang to follow him, a fearful Xin Chang turned to his sister for advice