Li Chengqian
Around the same time, however, Emperor Taizong's crown prince Li Chengqian was becoming fearful because Emperor Taizong had greatly favored another son, Li Tai the Prince of Wei, and Li Tai was making designs on the crown prince position. Li Chengqian therefore gathered a group of political and military officials around him to consider overthrowing his father, including his uncle Li Yuanchang () the Prince of Han, his cousin Zhao Jie (), and brother-in-law Du He (杜荷, Du Ruhui's son). Hou's son-in-law Helan Chushi (), the commander of Li Chengqian's guards, was also part of the plot, and through Helan, Li Chengqian invited Hou to join the plot as well, as Hou agreed. However, he was deeply disturbed by his own involvement, and he developed insomnia. His wife sensed that something was wrong, and told him, "You, Duke, are an important official of the state, so why are you acting like this? If there is something you are doing wrong, you should report yourself so that your life can be spared." However, Hou did not do so.