A passenger on the plane suddenly became crazy and encountered strong airflow on the plane. When everything stabilized, the passenger had died of sudden cerebral edema. And this passenger's identity is not ordinary. He is a senior researcher at a nanny unit and was monitored by relevant departments for suspected selling national intelligence to foreign spy organizations. His bizarre death caused the monitoring and pursuit to come to a standstill. At this time, the National Security Bureau arrested the deceased's younger brother Wang Hao. So they came up with a plan to let investigator Shen Kang (played by Sun Honglei) pretend to be Wang Hao, and then lure the snake out of the hole. And the middle contact with Wang Hao in this undercover pursuit is the flight attendant Li Xiaowan (played by Fu Jing) on the plane. The two of them fell in love with each other during their interactions. But the identity of the undercover must not be exposed, and Xiaowan is entangled with Wang Hao's identity as a gangster. As the investigation of the case deepens, the two face greater challenges...