Career woman Lin Chenxi (played by Tiffany Hsu) seems to have traveled through a parallel time and space after waking up from an accidental car accident. Her boyfriend Li Haoming becomes a policeman Xiao Liu (played by Li Chengbin) and is investigating the murder of her high school chemistry teacher Xie Zhizhong (played by Chen Yiwen). Is her high school classmate Yan Shenghua (played by Jia Jingwen) the main suspect? She pieced together and reconstructed her memory day by day, but found that something was wrong. The seemingly happy family and girlfriends gradually revealed unexpected truths with the murder case.