The female head catcher Li went to the northwest in January to investigate the case and met Tong Ling, the third prince of Beihai Long, and had feelings for each other, but was designed by the heart of the immortal to turn against him. In order to save their lives and erase their memories, the two have been separated ever since. Three years later, Li Yueyue and Tong Ling met unexpectedly, and the two fell in love with each other again by accident, and worked together to eliminate the nightmare and save the world.