In Shanghai in 1943, Chen Qian, a military agent, was ordered to assassinate the Japanese, but fell into the trap of Yujiro Ida, the head of Japan's plum agency. Born on the day, and accidentally learned of the Japanese conspiracy. In order to stop the sinister plan of the invaders, Chen Qian began to receive special training, disguised as a Japanese envoy to visit Mei's agency again. Chen Qian, who went deep into the enemy's camp, walked step by step in the dark, walking on thin ice, and with the help of the Communist Party member Chun Yang, he repeatedly avoided danger.

Ji Shu is a young writer of popular novels. His books are a hit among their many fans, but Ji Shu is blighted by emotional apathy and pessimism writer. His novels ultimately reflect this bleak outlook and almost universally end in tragedy. In many ways, he is the quintessential BE (bad ending) writer. By contrast, Song Yan Qi is an optimistic film and drama series planner. She loves happy ending (HE) stories. Song Yan Qi would like to adapt a Ji Shu novel for the screen but would ideally like to ensure the story ends happily – something Ji Shu cannot accept. But the duo’s lives are thrown into chaos when they are sucked into the world of the novel. As they begin to “live” the lives of Ji Shu’s characters, they begin to “rewrite” the story – and become drawn to one another. But will their own love stories end in joy – or sadness?