Wang Shen looked at Liang Zichen after asking. Liang Zichen glanced at Wang Shen and nodded.

"And stealing the key to change the beam is not only difficult, but also risky." Wang Shen pursed his lips and said with his eyes fixed on the door of cabinet 16.

"Team Wang, do you mean that the murderer has already guessed that we will use this key to open the door of cabinet 16?" Liang Zichen immediately understood the meaning of Wang Shen's words.

"That's right. You look at the distribution of the cabinets now. It is clear that the murderer restored all the cabinets to their original order. The purpose of this is obvious, to eliminate the last bit of hidden danger that we may find. But the murderer didn't expect that on the day of the accident, I would inadvertently photograph the whole cabinet and discover his tricks. However, after restoring the order of the cabinets, if we can't change the key in Ah Cheng's hand again, then what we are holding now is the key to cabinet 17. If that's the case, we won't be able to open the door of cabinet 16 anyway. In this case, the murderer's plan will be completely destroyed in an instant. In a short period of time, it is difficult and risky to realize the key drop. Wang Shen said his inference in one breath.

Liang Zichen kept nodding while listening to Wang Shen. "Since it's too risky to drop the key, how did the murderer let us open the door of cabinet 16 smoothly?"

"Maybe the key wasn't dropped at all, and the key to Cabinet 17 was the one we were holding?" Wang Shen looked at the key and the cabinet door and said his guess.

"We're holding the key to Cabinet 17, but we're opening Cabinet 16." Liang Zichen was confused by Wang Shen's words again, and couldn't figure out how the key to No. 17 could open the door of the No. 16 cabinet.

Wang Shen did not answer Liang Zichen's question immediately, but opened the cabinet door of No. 16 again. Wang Shen opened the cabinet door, approached the position of the lock cylinder inside the cabinet door, and carefully observed it for a long time.

Suddenly, a smug smile appeared on Wang Shen's face. "Herein lies the problem." Wang Shen pointed to the lock cylinder on the cabinet and said.

When Liang Zichen heard this, he immediately brought his eyes closer to the lock cylinder and carefully observed the lock cylinder. Liang Zichen stared at the lock cylinder for a while, and frowned slightly: "Team Wang, there is something wrong with this lock cylinder." ”

"Well, did you find out too?" Wang Shen smiled and responded.

"That's right." Liang Zichen nodded. "It looks like no one has cleaned this cabinet for a long time, so there's a lot of dust on the door. But strangely, the dust around the lock cylinder seems to have been cleaned irregularly. ”

Wang Shen nodded as he listened. "You've been careful to observe, but the dust around the lock cylinder shouldn't have been deliberately cleaned up, but accidentally rubbed off."

"Yes, I think so too. Not only that, team king, you look here. Liang Zichen pointed to a screw on the lock cylinder. This screw doesn't seem to be exactly the same as the rest of the screws on this lock. ”

"That's the biggest flaw. So can you now guess how the killer used to get us to use the key to cabinet 17 to open the door of cabinet 16? ”

Liang Zichen thought for a while, then nodded and said, "I guess this original screw was accidentally omitted by the murderer in the process of replacing the lock cylinder." That's why I found such a replacement in a hurry. The method used by the murderer to steal the beams and replace the pillars was to ensure that the cabinets were in the correct order, and then replace the lock cylinders. This way we can use the key of number 17 to open the door of cabinet number 16, which is clever! ”

"Yes, it all makes sense. Moreover, we did as the murderer expected, on the day of the crime, without this key, we would not have been able to see through his ruse. The smile on Wang Shen's face faded, replaced by a solemnity between his eyebrows. Therefore, the act of replacing the lock cylinder should be after we leave the store. And the murderer, I guess it should be the person in this store. ”

"Team Wang, do you mean Han Lin by 'the people in this store'?" Liang Zichen looked at Wang Shen, in fact, he also had such a guess in his own heart.

"Frankly, I think so. But such speculation is a bit arbitrary, after all, we have no substantial evidence in our hands. Therefore, our task is to collect evidence in many aspects. Wang Shen nodded, then shook his head slightly.

"Team Wang, wait, I found some other problems in the design process of this ruse." Liang Zichen looked at the cabinet, suddenly thought of something, looked at Wang Shen with a serious face and said. After the order of the cabinet is reversed, Ah Cheng needs to open or close his cabinet door, which must use the number 17 key. But what was placed next to Ah Cheng at first must have been the No. 16 key. To put it simply, the murderer must drop Ah Cheng's No. 16 key, replace it with the No. 17 key, and then let Ah Cheng use the No. 17 key to open the No. 17 cabinet and take away the prepared clothes and gloves. So how did the murderer steal the No. 16 key next to Ah Cheng and change the beam? ”

"I've thought of the answer to the question you said. The murderer is really a rare smart person. Wang Shen frowned slightly, looked at the cabinet in front of him and replied. First of all, the murderer must know Ah Cheng's living habits very well. After saying this, Wang Shen walked towards the small door inside the locker room. Wang Shen gently pushed the small door and walked in.

"How can there be a bathroom here?" Liang Zichen followed behind Wang Shen and asked in surprise as he looked at the small bathroom in front of him.

"Here is a small bathroom for employees, which is convenient for employees' lives." Wang Shen explained simply. "Not only that, I asked Han Lin about Ah Cheng's work habits. Ah Cheng comes to the store especially early every day, because Ah Cheng has a habit of taking a shower in the morning, probably to avoid other peak periods. ”

"But what does this have to do with key drops?" Liang Zichen was a little anxious, and he didn't seem to have the heart to listen to the story about this bathroom.

"Okay, then let's talk about the key drop. I ask you, when might the key drop happen? Wang Shen turned to look at Liang Zichen.

"When did the key drop? I can't guess. Liang Zichen looked at Wang Shen and shook his head, and then seemed to figure out something. No, in order to avoid flaws, the shorter the time it takes for the key to drop the bag, the better. Liang Zichen replied, and then Liang Zichen was silent for a while, and then overturned the previous inference. It's still not right, Ah Cheng has to open the cabinet to get something, and the clothes that have been splashed with gasoline can only be used once, so the time when the key is dropped should be within 24 hours before the crime. ”

"That's right!" Wang Shen gave Liang Zichen a thumbs up. "But to drop the keys in such a short period of time, you have to find a good time to start. When is this a good time? It was at this gap when Ah Cheng came to take a bath in the morning. Wang Shen said with a frown.