1978in 2019, on the train from dalian to sankeshu, a young police officer wang xin was injured in the arrest operation for the first time, but he became a disguise and met ma kui, an old detective in the railway policeman. the two became masters and apprentices and fought side by side in the first place in the railway policeman. ddd。 on this railway line, over the past 40 years, they have experienced the era of steam locomotives, electric locomotives, and high-speed trains, witnessing the great achievements of the motherland and the tremendous changes in people's lives. front-line railway police officers represented by wang xin and ma kui have rebeled, cracked down on trafficking, anti-drug, patrolled the line, guarded, cracked down on theft, robbery, and cracked down on gangsters and evil. for decades, they have solved major cases, solved small cases, and brought warmth and harmony to passengers. in order to protect the safety of people's lives and property, railway police officers even sacrificed their precious lives. the passengers coming and going on the train, carrying different imprints of each period, show the warmth and coldness of human feelings and the various aspects of life. the two generations of police officers have also been sublimated in their life experiences, and the loyal police spirit and torch have been passed down from generation to generation.