After the brutal war, Dong Yue (Yi Sun) goes back to the past to seek Feng Xi (Han Jin). She plans to work with Feng Xi to kill Yuantong Lu (Zhijian Zhang) in order to bring peace to the world. Unexpectedly, Feng Xi loses his memories. Dong Yue helps Feng Xi get back his memories, and both of them fall in love with each other. However, the biggest threat is still in front of them...