The two organized the evidence and put it back in the train attendant's office at the front of the train. Xiao Lou looked at the syringes and empty bottles on the table and asked thoughtfully, " Captain Yu, can we just search the passengers' backpacks? There should be some clues there."
Yu Hanjiang thought for a moment and said, "I remember in the Red Heart 3 escape room, when the students went to the playground, we searched their bags in the classrooms for evidence. This escape room should work too. The crew members' identities make it convenient for us to search at any time." He said decisively, "Let's try it and see."
Xiao Lou nodded and turned to follow Yu Hanjiang.
The two arrived at room number 1. Yu Hanjiang said calmly, "At the request of the security department, we need to conduct a simple security check on everyone's luggage. Please cooperate."
The passengers did not object, seemingly accustomed to the flight attendants' security checks.
An old man came over and asked Xiao Lou, "Is Old Li having a heart attack?"
Xiao Lou smiled and said, "There's no definite conclusion yet, sir. Could you please give me your backpack?"
The old man obediently handed him the bag, saying, "I didn't bring any flammable or explosive items; the bag is full of food."
Xiao Lou opened it and saw—sure enough, it was a big bag of food; this old man was a foodie.
He casually asked, "How many days are you going to stay in Moon City this time?"
The old man said, "Three days, then we'll fly back. None of us have much luggage."
Xiao Lou turned around and saw that everyone's luggage was a set of black backpacks purchased by the travel agency, with a luggage tag attached to each person's name to avoid confusion.
Yu Hanjiang checked the luggage under the pretext of "security check," and the other three cooperated by taking their backpacks off.
Only the old lady in bed 1A was still looking down at the newspaper. She was over seventy years old, with completely white hair, a hunched back, a face full of wrinkles, and she walked with a cane. She also had hearing problems. Everyone else took good care of her and called her " Sister Mei ".
Seeing that she didn't react, an old lady next to her gently shook her arm: " Sister Mei, the flight attendant needs to do a security check."
Sister Mei was startled by the shaking and looked up to ask, "What?"
The old lady yelled loudly in her ear, "The flight attendant wants to check the luggage!"
Sister Mei still looked bewildered: "What?"
Yu Hanjiang pointed to her backpack, signaling her to take it down. She finally understood the gesture and stood up shakily to get the bag. The old man next to her, seeing her difficulty moving, helped her out.
Yu Hanjiang opened her backpack and saw a few changes of old clothes, some blood pressure medication, a few newspapers, and nothing else.
The old man explained, " Sister Mei is old, her legs aren't very nimble, and her hearing isn't good either. She's the most senior colleague in our company. She's been in the HR department since the boss started the business. Most of us were recruited by her. Her daughter asked her to come out with us to relax, but she wasn't happy about it, saying it's too much trouble to go out."
Xiao Lou and Yu Hanjiang exchanged a glance. Since Sister Mei was the company's most senior employee, she must know something.
There was nothing unusual about her luggage, and Yu Hanjiang planned to question her alone later. She might be hard of hearing, but she could write; the elderly woman wore thick reading glasses, so she should be able to see clearly, right?
The two backpacks were fine, and Xiao Lou and Yu Hanjiang quickly checked the remaining two separately.
In one of the backpacks, Yu Hanjiang found some needles, cotton swabs, and a row of things that looked like ballpoint pens. He didn't recognize them, so he showed them to Xiao Lou. After examining them carefully, Xiao Lou whispered in Yu Hanjiang's ear, "These are insulin pens."
Yu Hanjiang flipped through the name on the backpack's luggage tag— Niu Dapeng.
He looked at the old man in bed C of room 1 and asked, "Uncle Niu, is this bag yours?"
Niu Dapeng nodded: "Yes."
Xiao Lou smiled and asked, "Uncle, do you also have diabetes?"
Niu Dapeng said, "I've had this problem for many years and have been relying on insulin to control it."
Yu Hanjiang then asked, "Did you know that Li Zhemin has diabetes?"
Niu Dapeng remained calm: "I know, Lao Li and I stayed at the same hospital before."
Yu Hanjiang made a note of this old man named Niu Dapeng.
The last bag showed nothing unusual. The two left room 1 and continued searching room 2.
Since the deceased lived in room number 2, this room needs to be thoroughly investigated.
The old man who had switched places with the deceased and slept on the upper bunk was the most conspicuously bald among the group; only half of his head was covered in gray hair, making him easily recognizable. This man was named Zheng Weiguo, and Yu Hanjiang found the same needles, cotton swabs, and insulin pen in his bag.
Yu Hanjiang asked, "How long have you had diabetes?"
Zheng Weiguo looked embarrassed: "I didn't pay attention when I was young. I often ate a lot of meat and fish. Five years ago, I was diagnosed with diabetes and high blood pressure. I have been using insulin and antihypertensive drugs to control it."
In addition, Yu Hanjiang also found a deck of cards in the bag of an old man named Liu Yuming. The old man explained, "Old Li likes to play cards. The four of us played 'Upgrading' last night and didn't go to sleep until 2 a.m.
Yu Hanjiang asked, "How do you play cards when the lights are out?"
Liu Yuming said, "I often need to go to the bathroom in the middle of the night, and my eyesight is poor, so I can't see clearly at night. This time when we went out, my son prepared a rechargeable lamp for me, so I could take it with me when I needed to go to the bathroom. Last night, the old man..."
Li Xiang was playing cards, so I turned on the rechargeable light and placed it on the upper bunk for illumination.
The other two nodded in agreement: "That's right!" "Old Li was having a good time playing cards last night, but I never expected... sigh."
These elderly people actually played cards until 2 a.m. with the rechargeable lights on; they're really going all out.
Yu Hanjiang asked him, "Did you go to the bathroom in the middle of the night last night? Did you see anything?"
Liu Yuming shook his head: "I got up once at three o'clock, but everyone was still asleep and all the doors were closed."
Yu Hanjiang asked, " Did Li Zhemin make any move at that time?"
After thinking carefully, Liu Yuming said, "I remember Old Li seemed to have turned over and was still snoring softly."
In other words, Li Zhemin died after 3 a.m.
There were no other suspicious items in the room. The two men went to room number 3 and were about to search the luggage when an old woman suddenly said angrily, "What right do you have to search my luggage? This is an invasion of privacy!"
She appeared extremely agitated.
This elderly lady is named Shu Ping. She is 60 years old, but looks only 40. Her skin and figure are very well-maintained. The fashion-conscious lady is wearing a dress, and her shoulder-length hair is permed. She is the youngest and most beautiful elderly lady in the group.
Yu Hanjiang calmly said, "It's a routine safety check. Please cooperate, Auntie."
Xiao Lou smiled and echoed Yu Hanjiang: "That's right, everyone else is very cooperative with the inspection. If you're worried about anything private, Auntie, you can come with us to the office alone, and we'll check it for you privately."
Shu Ping's face turned pale, and she clung to her bag, refusing to let go.
Her strange behavior drew the attention of the other three elderly people in the room. Yu Hanjiang frowned and said, "If you don't cooperate, I can only temporarily detain you and wait for the guards to handle it."
He reached out for the other person's backpack, and after hesitating for a long time, Shu Ping finally handed the backpack to Yu Hanjiang.
When Yu Hanjiang opened it, besides a change of clothes, he found insulin again in the hidden compartment at the bottom of the backpack... However, wasn't this dosage a bit too much? It was almost twice the amount found in Niu Dapeng and Zheng Weiguo's backpacks.
When they found these things, the old lady's face immediately turned extremely ugly.
Xiao Lou smiled and asked, "Auntie, how many years have you had diabetes? Why are you carrying so many medications?"
Shu Ping snatched the backpack and said with a stern face, "It was diagnosed last year. My condition is quite serious, and I need to take more medication, so I carry more medicine than the average person."
The old lady next to her looked at her in surprise: "Xiaoping, you have diabetes too? Why didn't you tell us?"
Another person said, "Yes, diabetes isn't a shameful disease. Many elderly people get it. Why are you hiding it from everyone?"
Shu Ping's face turned pale and then red, and she stammered for a long time without being able to answer.
Xiao Lou and Yu Hanjiang exchanged a glance, then turned and left the room.
Other passengers cooperated with the inspection, but most of them were not related to the senior citizen group, and their luggage was full of food and clothes.
After checking the entire carriage number 6, the two returned to the attendant's office at the front of the carriage.
Space is limited on the high-speed train. The attendant's office is only about 1.5 square meters, with a small table and a chair. Two big men standing inside would feel cramped, their bodies almost touching.
Yu Hanjiang is not used to being so close to people. When talking to someone too close, his breath would brush against the other person's face, which he felt was very impolite.
He offered, " Professor Xiao, please have a seat."
Xiao Lou didn't stand on ceremony and sat down in the chair, giving Yu Hanjiang more space. Xiao Lou looked up at Yu Hanjiang standing beside him and asked, " What does Captain Yu think?"
Yu Hanjiang leaned against the table, his long legs casually crossed, his arms clasped in front of his chest, and said in a low voice, "Currently, there are four clear suspects— Niu Dapeng from room 1, who used to be hospitalized with the deceased. The two were fellow patients at the same hospital, so he must have known about the deceased's diabetes."
" Zheng Weiguo, who lived in room number 2, slept in a bunk bed with the deceased. They played cards together until 2 a.m. last night. He could easily tell whether the other people in the room were asleep, which made it easier for him to commit the crime while Li Zhemin was asleep. Moreover, he was also a diabetic."
" Liu Yuming in room 2 said that he often went to the toilet in the middle of the night, but it is also possible that this was just a cover-up. He got up at three o'clock in the morning, killed Li Zhemin, pretended to go to the toilet, and threw away the syringe and insulin bottle so that no one would suspect him."
"And then there's Shu Ping in room 3. When they searched her luggage, this old lady was unusually agitated. Her insulin was hidden at the very bottom of her backpack, and the dosage was twice that of everyone else. Her condition was serious... It just doesn't make sense."
Xiao Lou stroked his chin, seemingly lost in thought.
Yu Hanjiang asked, "What are your thoughts?"
Xiao Lou said, " Captain Yu, did you notice that the insulin that some of the elderly people were taking was different from the insulin we found in the trash can?"
Yu Hanjiang nodded: "The insulin they brought was something like a ballpoint pen, which is what you call an insulin pen?"
Xiao Lou casually rested his right hand on the table, his slender fingers slightly bent, his index finger tapping lightly on the surface as he earnestly analyzed: "I have a classmate who is an endocrinologist. Currently, the most commonly used treatment for diabetes is this kind of 'insulin pen,' which is convenient to carry and also eliminates the hassle of drawing up the injection with a syringe."
He paused, then continued, "Insulin pens use finer needles, which reduces pain. The dosage is clearly marked on the pen, and the cartridge can be replaced easily. You just need to carry it with you when you go out."
Bringing enough pen refills makes daily injections very convenient.
To help Yu Hanjiang understand better, Xiao Lou gave an example: "It's like the difference between a ballpoint pen and a traditional fountain pen. With a ballpoint pen, you can just replace the refill when it runs out of ink, and the refills are easy to carry. However, with a fountain pen, you need to draw ink from the inkwell, and it's hard to control how much ink you draw, so carrying ink around is inconvenient. It's like a traditional syringe; drawing insulin is troublesome and not easy to carry. So in clinical practice, insulin pens are basically used for injection."
Upon hearing a lot of professional knowledge, Yu Hanjiang immediately understood: "You mean, the traditional syringes and injections found in the trash can don't belong to Li Zhemin?"
Xiao Lou nodded: "That's right. Li Zhemin is so rich, and insulin pens are very convenient to carry and use. There's no reason why other old men and women would know how to use insulin pens, while he would still use the most outdated syringes to inject himself."
Xiao Lou picked up a ballpoint pen and quickly wrote a formula on the notebook, saying, "There's another question. I just thought about it carefully. The dosage of insulin can be estimated using this formula. Aunt Shu Ping is very thin, weighing at most 50 kilograms. That means her daily insulin dosage is about 20 units. The amount of insulin in her bag is enough for her to use for a month."
Yu Hanjiang glanced down at the calculation formula—
[Fasting blood glucose (mmol/L) × 18 - 100] × 10 × weight (kg) × 0.6 ÷ 1000 ÷ 2...
Xiao Lou's handwriting is elegant and neat; it's a wonder he could remember such a long formula.
Yu Han lowered his head and pondered for a moment, then speculated, "According to your analysis, the syringes and needles in the trash can don't belong to Li Zhemin, because the equipment Li Zhemin uses to treat diabetes is definitely a high-end 'insulin pen,' not a traditional plastic syringe. However, we didn't find insulin in Li Zhemin's bag; instead, we found an excessive amount of insulin in Shu Ping's bag. So, it's highly likely that— Shu Ping stole all of Li Zhemin's insulin?!"
Captain Yu's logic is impeccable; he instantly understood Xiao Lou's meaning.
Xiao Lou nodded approvingly and said, "I asked tour guide Xiao Qin, and their senior citizen tour lasts a total of ten days from departure to return. They will be flying directly back. Aunt Shu Ping brought a month's worth of insulin cartridges, which is completely unnecessary."
A 10-day trip, with a 30-day supply—that's a supply for two people.
It seems that Lao Li has offended quite a few people; this Shu Ping actually stole all his insulin!
Yu Hanjiang gathered his thoughts and said, " Shu Ping looked unwell just now and didn't want us to check her bag because she stole Lao Li's insulin and was afraid we would find out—this woman has a lot of problems."
Xiao Lou followed up, saying, "However, the culprit who injected Lao Li with nearly 300U of insulin at once using a traditional syringe may not necessarily be Aunt Shu Ping. If it were her, she wouldn't have gone to the trouble of stealing Lao Li's insulin cartridge."
Yu Hanjiang agreed: "It seems we need to continue the investigation; this group of elderly people is really not simple."
Just then, tour guide Qin Shiyue came over with a stack of documents.
After adjusting her mindset, the young woman looked much better. She knocked on the door of the flight attendant's office, handed the documents to Xiao Lou, and said, "Our travel agency has high requirements for senior citizens' registration. The registration form must be filled out in detail. Here are the registration forms for 12 passengers, including their family information and past medical history, all of which are recorded."
Xiao Lou nodded to her: "Thank you."
Qin Shiyue was silent for a moment, then clenched her fist and said, "If it really is murder, we must find the killer!"
"Don't worry, we'll find out as soon as possible." Xiao Lou was focused on reviewing the documents, so Yu Hanjiang said casually, "Xiao Qin, let me ask you a few questions. How long have you been with these 12 people? Which of them have a good relationship with Li Zhemin?"
Qin Shiyue frowned and thought for a moment before saying, "I took them to Sun City for three days. Old Li is well-liked in the group, and most people like to flatter him. His son is extremely rich. Before, in Sun City, he treated all of us to a seafood feast at a high-end restaurant, which cost hundreds of thousands of dollars in one meal. He is also very loyal. If anyone asks him for a favor, he will readily help them."
Yu Hanjiang asked, "He hasn't had any arguments with anyone?"
Qin Shiyue shook her head: "The past few days I've been leading them, everyone has gotten along quite well. They've been chatting and laughing the whole way, and nothing seems out of the ordinary. Last night, Old Li even treated everyone to dinner in the dining car."
Yu Hanjiang asked, "Does no one dislike him? For example, does anyone show any disgust towards him in private?"
"Well..." She scratched her head and thought for a moment, then said, "Uncle Niu is the one who dislikes him the most. He never talks to him, they don't sit at the same table when they eat, and they act like they don't know each other when they meet. Oh, and there's Aunt Shu Ping. She always rolls her eyes behind my back. I've seen it many times. When Old Li is praising his son, Aunt Shu is sneering."
Yu Hanjiang then asked, "Are the three people in room number 2 closest to Lao Li?"
Qin Shiyue nodded: "When they bought the tickets, their seats were not together. Old Li said he wanted to play cards with his brothers, so he specially asked me to pay for a change of seats at the ticket office, so that all four of them could be put in the same room."
This aligns with the findings of the investigation in room number 2; the four old men did indeed play cards until 2 a.m. last night.
Xiao Lou suddenly looked up from the pile of documents and asked, "Does Old Li sleep very soundly?"
Qin Shiyue paused for a moment, then nodded and said, "It seems so. Everyone says he's easygoing. His son is so rich and filial to him, and the family owns several houses. He has nothing to worry about, so he sleeps very soundly and can't be woken up by thunder."
The tour guide had very little time to interact with this group, and knew...
With limited information, Yu Hanjiang let her go after getting a general idea of the situation, and instructed her, "Could you please go and call Shu Ping over?"
Qin Shiyue turned around and went to room number 3 to call Shu Ping.
The youngest and most beautiful old lady in the group, who usually always put on a proud demeanor, turned pale at this moment.
She took a deep breath and, feigning composure, approached the flight attendant's office, where she saw two people, one standing and one sitting.
The handsome man sitting there had refined features and a gentle expression, and seemed very approachable.
The man standing there had a sharp gaze as cold as ice. Shu Ping was so frightened by his cold look that her legs trembled. She was wearing very thin high heels and almost twisted her ankle. She hurriedly grabbed the doorknob next to her to steady herself.
Yu Hanjiang said calmly, "Speak, why did you steal Li Zhemin's insulin?"
Shu Ping: "..."
Author's Note: Captain Yu is good at playi