Yu Xinxins words shocked Xiao Lous spirit. She heard an obvious cough which meant that Liu Yuming wasnt the only one who went to the toilet last night!

Xiao Lou smiled at her and continued to ask, Xinxin, do you know the time when you heard the cough?

Yu Xinxin coughed her head and thought about it. It should be 3:10. I went to the toilet and back to my seat. Then I looked up at the time on the carriages screen.

Xiao Lou quickly picked up a pen and paper and wrote down the key information.

He followed up by asking, Then did you hear or see anything else?

Yu Xinxin said, The grandmother seemed very ill and coughed for a while. Then her voice got further and further away from me and I couldnt hear her anymore. The strange thing is that after the grandmother walked far away, a dark shadow emerged from the dining carriage and headed in the direction of the 6th carriage.

Xiao Lou asked, How tall is the dark shadow? Is it fat or thin? Do you remember?

Yu Xinxin carefully thought about it for a few seconds. They should be very thin, definitely not far! I couldnt see how tall.

Then? Xiao Lou asked another question. Was there anyone else who went to the toilet?

Yes! After a few minutes, um at around 3:30, I saw a light from the side of the 6th carriage. The light was obvious and there was a strange sound coming from the trash can.

Xiao Lou was surprised. This obvious light should be Liu Yuming going to the toilet. He was the only one who brought a charging light with him.

In the previous questioning, Liu Yuming said he went to the toilet at 3 oclock while the little girl said 3:30. It was a time difference of half an hour. The child wouldnt lie so Liu Yuming was obviously lying!

Uncle, there shouldnt be any rats in the carriage, right? The little girl looked up seriously.

There are no rats in the carriage. Maybe someone accidentally hit the trash can. Xiao Lou smiled and softly asked, How long did that sound last?

It was a few seconds. Yu Xinxin smiled. I also thought at that time if it was a mouse in the trash can and someone got up to catch the mouse!

Xiao Lou touched the childs head. In addition to the sound, did you see anything?

Soon after the sound of the trash can ended, the red lights of the two toilets in the 6th carriage lit up.

In the moving train, there would be a toilet reminder on the roof. If no one was in the toilet then it was a green light. Once someone entered the bathroom and locked the door, it would become red.

There were many passengers on the train. This setting was for the convenience of the passengers to let them know if the toilet was free. If they wanted to go to the toilet and could see that both were occupied, they could wait for a moment for them to finish.

Xiao Lou didnt expect that this simple light prompt would become a key clue to this case!

The little girl said there was a bright light, a strange sound from the trash can and then both toilets became occupied. This showed that when Liu Yuming went to the toilet, another person entered the toilet opposite him.

There were two people in the toilet at the time yet Liu Yuming didnt mention it.

Xiao Lou then asked, Both bathrooms had a red light. Which side turned green first?

The little girl said, The left side of the toilet quickly turned green and the elderly man with the light went far away. The right side had a red light for a long time. Maybe someone had diarrhea!

Yu Xinxins mother heard up to here and she couldnt help feeling tense. Whats wrong with the 6th carriage? Why are you asking my daughter about what happened last night?

Xiao Lou gave her a reassuring look. It isnt a big deal. An old man lost valuable jewellery and we need to carefully investigate to find the thief. He looked back at the child. Xinxin also hates thieves, right? So you should tell me everything you saw and heard, okay?

Xiao Lou coaxed the child and he was also kind and gentle. Yu Xinxin liked this train attendant uncle and in order to cooperate with the arrest of the thief, she actively worked her brain.

I couldnt sleep after going to the toilet last night. The rest of the carriage was sleeping so I sat on my seat and looked at the stars outside.

The man with the light left and there was suddenly a meteor shower outside the window. It was beautiful! I watched the meteor shower for 10 minutes. Then in the 6th carriage, there was the sound of hurried footsteps. I didnt see it clearly but a person went near the dining carriage. They didnt go to the toilet and suddenly turned back. Immediately following, the toilet door on the right opened and the light turned green.

It was around 3:40 and there were two coughs in the carriage. Then I was sleepy and fell asleep.

Xiao Lou wrote down her answer without missing a single word.

Yu Xinxin looked curiously at him. Uncle, did my words help?

Xiao Lou smiled softly. Xinxin was great. Your words were very useful and we will definitely catch the thief.

Xinxins eyes curved. Thats good!

Later, she fell asleep and didnt know anything else. Xiao Lou had no more questions and let Yu Xinxins mother take her away. Goodbye, Uncle!

Xiao Lou said goodbye to the little girl. He turned in the direction of the 6th carriage and had just walked past the 8th row with Zhao Zheng stopped him and whispered, Someone died in the 6th carriage?

Xiao Lou turned back and wondered, How do you know?

Zhao Zheng took out his phone and showed Xiao Lou a WeChat message from his girlfriend Mo Jiaran.

There was a long list of WeChat records: An old man died in the 6th carriage. The train attendant locked the door of the carriage and isnt letting anyone out. He is checking the passengers luggage one by one. Too scary!

Zhao Zheng: What is the situation? How could a person die?

Mo Jiaran: I dont know. Listening to the outside conversation, it seems to be a sudden heart attack or something. The elderly people of the tour group are very nervous. I dont want to stay in the 6th carriage. Can you come to pick me up?

Zhao Zheng comforted her: Dont worry, Ill ask the attendant.

He took back his phone and whispered to Xiao Lou, Can you let my girlfriend come back to the 4th carriage. She is alone over there and Im worried.

Sorry, were still investigating and we cant let anyone leave for the time being. Dont let her publicize it and send her a message telling her to stay in her room. It has nothing to do with her and we wont embarrass her.

Zhao Zheng frowned. Okay.

He had a headache and was afraid he wouldnt be able to persuade this young lady. Xiao Lou was also afraid of her making a fuss and went to the 6th carriage to comfort Mo Jiaran. Miss Mo, dont worry. We will soon have results for our investigation. At that time, we wont stop you if you want to go back to the 4th carriage.

Mo Jiaran looked pale as she nodded.

Xiao Lou turned to the attendants office of the 6th carriage. Yu Hanjiang was frowning and looking at the transcript of the interrogations.

The two peoples eyes met and Yu Hanjiang stood up. Professor Xiao, sit.

Xiao Lou smiled and shook his head. Its fine. Group Leader Yu, you sit. I have Yu Xinxins testimony here and I want to show it to you.

He closed the door of the office and leaned against the table. He picked up Yu Hanjiangs interrogation of Mrs Mei and read carefully.

The office was quiet as both of them looked at the result of the other persons inquiry.

This case was much more complicated than they thought.

A few seconds later, the sitting Yu Hanjiang picked up his pen and drew a plan of the carriage.

He pointed to the picture and analyzed, The dining carriage is in the middle, the left is the 6th carriage and the right is the 4th carriage. Since the dining carriage doesnt have a toilet, it shares two toilets with the 6th carriage. Yu Xinxins seat is at the end of the 4th carriage and this happens to be close the dining carriage. Therefore, she can clearly see the light prompt at the top of the carriage.

Yu Hanjiang followed with a drawing of the distribution of the elderly people. Rooms 1, 2 and 3 are far from the toilet. They need to cross the entire carriage in order to reach the toilets near the dining carriage.

Xiao Lou glanced at the testimony doubtfully. According to Yu Xinxins description, she had an obvious cough. This coughing should belong to Mrs Mei? You wrote that she has obvious asthma and coughed while answering questions.

Yu Hanjiang nodded. It should be here. The murderer committed the crime in the middle of the night and it is impossible to make too much noise. What if the coughing woke up the people in the other carriages and they opened the door to see the situation. Thus, there is only one explanation. Mrs Mei couldnt help coughing when she went to the toilet at 3 oclock at night.

Yu Hanjiang simply picked up the ballpoint pen and sorted out a timeline according to Yu Xinxins words.

At 2:00, Li Zhemin and the three old men stopped playing cards and slept.

At 3:10, Mrs Mei got up to go to the toilet and coughed. Yu Xinxin also saw a shadow appear in the restaurant.

At 3:30, Liu Yuming held up the light to go to the toilet and there was the sound of rats coming from the trash can that lasted for a few seconds. Another person entered the toilet opposite Liu Yuming and the red light of both toilets turned on.

At around 3:40, someone wanted to go to the toilet and walked halfway there, only to hurry back. At this time, the person finally emerged from the opposite toilet and coughing filled the carriage. Then Yu Xinxin fell asleep.

The time was well organized.

Still, so many people went to the toilet. Xiao Lou couldnt help holding his temple to endure his headache. The sound of coughing, the light, the trash can sound, the hurried footsteps away

It seemed that there was a surging undercurrent in the 6th carriage last night!

Yu Hanjiang looked at the timeline in the book and fell into contemplation.

Moments later, he started to read the clues one by one. At 3:10, the old lady went to the toilet when a figure appeared in the restaurant. There is a possibility that when the murderer was about to commit a crime, they heard the old lady coughing. In order to avoid being found by the old lady, they hid in the restaurant.

Xiao Lou felt this was very reasonable. Otherwise, what did they run to the restaurant in the middle of the night to do?

He agreed. It makes sense. If they were simply going to the toilet then there is no need to hide in the restaurant from Mrs Mei unless there is an ulterior motive in their heart. It seems that the person hiding in the restaurant is probably the murderer.

Yu Hanjiang pointed to the third timeline. Liu Yuming is lying. He deliberately confused the time and the reason for looking for a watch was made up. Xinxin said there was a strange noise from the trash can that lasted a few seconds. He wouldnt be able to find his watch in a few seconds.

Xiao Lou nodded. Yes, it only lasted a few seconds so the most likely possibility is that someone hit the trash can in a panic. This perhaps might the murderer hiding in the restaurant. They wanted to go back only to meet Liu Yuming and had to hurry into the toilet.

Yu Hanjiang said, When Liu Yuming went to the toilet at 3:30, the opposite toilet also had its red light turn on. Your analysis is very reasonable. The person in the restaurant wanted to return to the 6th carriage and happened to encounter Liu Yuming. They could only hide in the toilet. They stayed in the toilet until 3:40.

Yu Hanjiang circled a few key points on the book. The time 3:40 is critical. There are three people at the same time. The first is the one hiding in the toilet who came out when they felt it was safe outside. Another person was going to the toilet only to turn back halfway. They probably saw someone coming out of the toilet and hurriedly turned to run. Finally, there is Mrs Mei who started coughing again at night.

Xiao Lou frowned and thought about it. Li Zhemins time of death should be after 3:40. Then it seems this time person of 3:10-3:40 had many elderly people going to the toilet, causing the murderer to constantly encounter other people. They first went to the restaurant to hide and then the opposite toilet. The last time they came out of the toilet, they probably ran into Mrs Mei?

Xiao Lou pointed out a key thing. The person who kept hiding was probably the murderer. Otherwise, there was no way to explain why they repeatedly evaded their acquaintances in the elderly tour group.

The last time, Mrs Mei woke up late and Xinxin fell asleep, not seeing what happened afterwards. Did the murderer hide or did they finally fail to escape and were found by the old lady?

If it was the latter then Mrs Mei was definitely protecting the murderer.

Xiao Lou reread the testimony of these people. Mrs Mei and Niu Dapeng live in a room. Since Niu Dapeng knows that Liu Yuming next door goes to the toilet with a light, it is impossible for him to not know that Mrs Mei went to the toilet. Niu Dapeng deliberately concealed it.

Yu Hanjiang added, Liu Yuming confused the time he went and made up an excuse of going through the trash can to find a watch. He is also lying.

Zheng Weiguo said he got up early in the morning to find the loan note in the deceaseds pocket. This is apparently also a lie.

Both men pinched their brows with a headache at the same time.

Everyone was lying. If it wasnt for Yu Xinxin reorganizing the timeline, they wouldve been dazzled by the groups lies.

Yu Hanjiang was helpless. Then it is very likely that Mrs Mei is covering up the murderer. Li Zhemins popularity is too terrible.

Xiao Lou took a deep breath and rearranged his thoughts. At present, Liu Yuming and Mrs Mei can temporarily be excluded. Their presence startled the murderer and forced them into hiding. Then the murderer might be among Niu Dapeng and Zheng Weiguo. Niu Dapeng is tall and fat. Xinxin said the person was thin. Isnt it more likely to be Zheng Weiguo?

Zheng Weiguo owed a gambling debt and stole the IOU note. He had a motive and sufficient time to commit the crime.

Why did he admit to stealing the IOU? Now that the IOU was destroyed, no evidence would be found if he didnt admit it.

Xiao Lou always felt there was something wrong.

Just then, Yu Hanjiang suddenly narrowed his eyes. I think that the person at 3:40 who went halfway to the toilet before going back is Zheng Weiguo.

Xiao Lou felt some surprise. Why do you say that?

Yu Hanjiang glanced at Xiao Lou and whispered his analysis, We can calculate it. At 3:30, Liu Yuming went to the toilet with his light. At that time, Zheng Weiguo in the same room might be awake. He found that his friend went to the toilet and the other two people are asleep. Thus, he climbed out of bed and took the opportunity to take away the loan note in Li Zhemins pocket.

Liu Yuming went to the toilet and soon came back to sleep. Zheng Weiguo listened to the people in the room. Once Liu Yuming fell asleep, he secretly got up and went to the toilet to get rid of this note.

The IOU note hadnt been found.

This moving train was a fully enclosed vehicle and the windows couldnt be opened. Throwing it in the garbage can could be easily found by the train attendants. The train was completely non-smoking and fire-free. Once ignited, it would directly trigger the smoke alarm.

Hiding the loan note in the bag wasnt safe. In order to destroy it, the best way was the toilet!

If he tore up the note, threw it into the toilet and let the water wash it out, this would destroy the evidence.

He didnt expect that when he got up, a person would suddenly come out of the toilet. Therefore, Zheng Weiguo guiltily hurried back and according to Group Leader Yus previous speculation, directly ate the IOU note.

Group Leader Yus logic was reasonable. Otherwise, who would go to the toilet in the middle of the night, only to turn back halfway?

It seemed that Zheng Weiguo was unlikely to be the murderer. He just stole the loan note and didnt kill anyone. The murderer had been hiding in the restaurant and then the toilet before leaving the toilet at 3:40.

It wasnt Zheng Weiguo, Liu Yuming or Mrs Mei.

Xiao Lou opened his mouth. Then it is Niu Dapeng? However Xinxin said the shadow is very thin. Niu Dapeng is tall and fat.

At this point, his eyes suddenly lit up. It seems there is a person who has been ignored by us!

Yu Hanjiang nodded solemnly. The first aunt Shu Ping, who was excluded by us.

Xiao Lous mind flashed over Shu Pings testimony.

She introduced her daughter to Li Zhemins son and as a result, Li Zhemin scolded her daughter for not being educated. She was angry and stole Li Zhemins insulin to teach him a lesson. At that time, the two people thought that if she was the murderer, there was no need to steal the superfluous insulin. Combined with the lack of motive, they excluded her first.

Her testimony seemed reasonable and her suspicion was decreased. There was one key point.

Yu Hanjiang stated coldly, No one can testify to her claims.

Everyone could testify that Li Zhemin stole Niu Dapengs manager position and had years of grievances.

Zheng Weiguo stole the loan note and Liu Yuming had seen the loan note.

Liu Yumings first love was pried away by Li Zhemin and most people knew about it. Mrs Mei could also testify to it.

However, who could prove Shu Pings words? Only the dead Li Zhemin knew the truth!

She said it one-sidedly that Li Zhemin called her daughter uneducated and she wanted to get revenge on the other person. She mentioned the contradiction between her and Li Zhemin but there was no third person to witness it.

In fact, from the beginning, Shu Pings testimony was the most implausible!