Lan Zhu and Jiu Shi accompany Tan Zao Zao to her third Door. The clue is the Waverly Hill Sanitorium, where a pregnant nurse committed suicide by jumping out of room 502. No one knows who the father is or why she jumped. Going against her leader’s instructions, Xia Jie orders Jiang Ying Rui to kill Xiong Qi’s friend, Meng Meng, in the sanatorium to frame Jiu Shi, who Xiong Qi is trying to recruit. (Source: frankly at MyDramaList)