1962, Tieli County in Northeast China. The inspector was inspecting the railroad tracks and vaguely saw a humanoid object in front of him. He hoped it was the cold morning fog that made him wrong. Soon, he approached the lying "person". His eyes didn't deceive him. There was a crushed body next to the railroad. The body was quickly taken back to the police station. At first everyone thought he committed suicide by lying on the railroad tracks. However, after the autopsy, they found signs that were not suicide. The female corpse was about twenty years old. She was covered in cuts and bruises. She seemed to have had a fight with someone else. Various details made the police begin to doubt the nature of the case.

What the police saw was definitely not evidence of suicide, but a thin strangulation mark on the neck of a female corpse. Police carefully investigated the area near the tracks and found no one around the track where the body was found. It was impossible to find witnesses. After inspection, no personal belongings such as the woman’s luggage were found. The police sent people to visit surrounding residents to try to find out the identity of the deceased. However, none of the nearby residents knew the woman, and there were no missing persons. This shows that the woman is probably a foreigner. Why does a foreigner travel so far? Who is this woman?

Tieli County is a small county and has not had any criminal cases for many years. Most of the residents who live here are kind. The sudden occurrence of a criminal case is terrifying. At that time, the media network was underdeveloped and rumors were flying everywhere. Everyone wants to catch the murderer as soon as possible. Because there were no witnesses and no surveillance, there was very little information about the victim that could identify him. The police can only start from the railway where the accident occurred. After re-investigation, the police realized that if the deceased did not commit suicide, he might have been pushed from a vehicle. As long as the car is found, the passengers of the day can be found, including the murderer.

The police found blood stains and some human body parts in the wheels of seven or eight carriages of a train. The strange thing is that this train is a truck and passengers are not allowed to ride on it. So how did the victim and the murderer appear in the car? Because the four flight attendants all had alibi and did not pay attention to the situation in seven or eight carriages, the case suddenly reached a deadlock.

While the police were confused, investigators found a well-preserved letter in the middle of the deceased's pants. The letter asked the deceased to work on the railway system and to introduce his nephew to the deceased. The new signature is a man named Han. After the police checked all units of the railway system, there were more than 20 Koreans. The police believe that since the work can be arranged, Secretary Han is the most suspicious. At the same time, the police intercepted a telegram sent from Shandong to South Korea. Based on this telegram, the police identified the deceased.

The deceased was Han Dong, his secretary in his hometown. She is 19 years old and her name is Huang Lianmei. However, after comparing the handwriting of the letter, it was found that the handwriting of the biggest suspect, Secretary Han, was completely different from that of the victim. Han's secretary himself has never contacted Huang Lianmei. Police searched for the remaining people named Han but found no one matching the letter's handwriting. The case has reached a deadlock again. A year later, handwriting experts reported a clue.

When the handwriting expert went out to work, he accidentally discovered that the handwriting on the poster was exactly the same as the Hanzhai in the letter. He concluded that it was written by one person. During the arrest, plainclothes police officers from two streets away were sent to understand the situation in order not to alert the suspect. The criminal suspect Qiu had heard about this. After a slight delay, Qiu ran away. Skynet is slow and slow. Qiu bought a ticket to Changchun, but the police were already waiting at the station. After a hunt, Qiu was finally arrested in a forest and brought to justice. After the trial, Qiu admitted that he accidentally saw Huang Lianmei's photo and pretended to be her to trick her into getting into trouble. During the battle, Qiu killed Huang Lianmei and threw the body off the train.