The prototype of Ningyang is actually Shenyang. Most of the plot background of South to North is that before 2005, the Ministry of Railways was still a four-level management model, and the Ningyang Railway Police Branch in the play should be a public security branch under the Ningyang Branch of Ningyang Railway Bureau. Captain Hu was the police captain of Ningyang Railway Police Branch at first, but Wang confessed that he chased the thief at 1968, and he was indeed on the scene. He accidentally pushed the thief off the train. Then go to the Ningyang Railway Police Branch and turn yourself in. At this time, Captain Hu has become the director (judging from the director sign hanging in his office, he is the director of the department, not the deputy director).