As soon as the words fell, Ye Yu took a sharp step and quickly walked towards the corner of the white wall. I saw him crouch down, put his head together, and look horizontally and vertically at a row of words in the corner.

"Did you find something?" Seeing this, Xiaolu hurriedly stepped forward and followed Ye Yu's line of sight.

The parts of the angry sentences overlapped each other, which seemed a little messy, but Ye Yu's eyes only focused on a certain sentence in the corner:

"It's going to cost you!"

The scarlet "blood letter" is full of hatred, and even after washing, it still looks dazzling against the white wall. Xiao Lu pondered this sentence, and did not see anything noteworthy other than the obvious threat, so she asked suspiciously:

"Is there anything wrong with this typography?"

Ye Yu didn't answer, but clicked on the photo on the phone again, compared it carefully, and then he took out the key he carried with him, gently scraped the wall skin somewhere on the wall of the "blood word", spread it in his palm, and carefully twisted it with his fingers.

Seeing that Ye Yu was focused on thinking, Xiao Lu stopped interjecting and quietly waited for Ye Yu's answer.

After a while, Ye Yu finally stood up slowly, he stared at the handwriting on the wall again, speechless for a long time, as if thinking about something, and finally said quietly:

"There is indeed a problem with this typography, but the problem is not the content, but the ......"

Halfway through his words, Ye Yu suddenly seemed to think of something, and quickly turned around and looked up at the ceiling.

I saw that on the ceiling several meters high, several rows of sprinkler-like objects were regularly inlaid with them.

"Is that the smoke alarm you mentioned earlier?" Ye Yu pointed to the disc-shaped sprinklers arranged at fixed intervals on the ceiling, and asked the bald man behind him.

"Yes, that's it." The bald man nodded in affirmation. "Because the classrooms are relatively large, there are a lot of them, and as long as a certain amount of smoke is sensed in the corresponding area, the smoke alarm device above the area will automatically sound the alarm and sprinkle water."

"Then you said that the smoke alarm device was broken and not repaired, did you mean that there was a problem with all of these?"

"Oh. Not really, this is the only row that has problems. The bald man reached out and pointed to a row of sprinklers not far above his head. Some students reported that there were several times when the sprinkler started to spray water by itself when there was no fire, but fortunately it was not class time, otherwise it would be troublesome for the students who were drenched in class, so the principal asked me to fix it as soon as possible. ”

"Have you had it a few times before...... Is it non-school time every time there is a breakdown? ”

"That's right, basically when there is no one in the lecture hall after school, I didn't delay anything, but it's a little annoying to have to scrub the desk every time......" The bald man shook his head and said helplessly.

"Is that so...... If my reasoning is correct, it's not good...... But now the most critical point is still missing......" Ye Yu lowered his head and muttered to himself. His eyebrows furrowed slightly, and then as if he thought of something, he quickly turned around and walked to the rows of conjoined desks behind him, and began to ignore the two people around him, leaning over to himself, looking for something under the desks one by one.

"Sir, what are you looking for......" The bald man looked at Ye Yu with a confused expression, and just wanted to step forward to ask, but was stopped by Xiaolu reaching out his hand. Signal the other person not to disturb. After a while, an excited shout came from Ye Yu's side.

"Found it!" Ye Yu straightened up, his face full of excitement. "Looks like I'm right!"

"What did you find......

The bald man just spoke, but saw Ye Yu suddenly look at him. Straight forward to the new requirements:

"I'm going to watch the surveillance video at the entrance of the lecture hall again, right now!"

The bald man looked dazed, but he couldn't withstand Ye Yu's firm request, so he could only lead the two back to the guard room again. turned out the surveillance video that Ye Yu requested.

"That...... I've watched the video before and after the accident a few times, and you've seen it too, so are there any questions? The bald man looked at Ye Yu, who was alone in front of the large monitoring screen and was concentrating on debugging the video. Full of confusion, but he didn't dare to come forward to ask, so he could only cautiously ask Xiaolu on the side.

"Hehe, just look at it~ Our Investigator Ye seems to be about to show his might~" Xiaolu was still calm, and seemed to be very relieved of Ye Yu, and the bald man saw that Xiaolu said this, so he stopped talking about it with interest.

Twenty minutes later, Ye Yu finally stopped what he was doing, and his frowning brows gradually stretched.

"It seems ~ that you have solved the mystery of this secret room?" Xiaolu looked at Ye Yu's confident appearance and said with a smile.

"Eight or nine is not far from ten." Ye Yu said, looking at the bald man again. "I remember you said earlier that there would have been an important meeting in this classroom on the afternoon of the discovery of the Scarlet Letter, right?"

"Yes...... Yes......" The bald man was stunned, as if he was startled by Ye Yu's sudden question. "Fortunately, the place was changed that day, if the sprinkler head here broke down and sprinkled water during the meeting of the leaders of the Education Bureau, then my job would be ruined......

"Hehe, I think you should be thankful that this thing is broken, otherwise your job would have been smashed." Ye Yu chuckled. "Also, since the accident, you're sure that only your individual security guards who are cleaning the walls have entered this place, right?"

"Yes, that's right......"

"That's fine, I think I already know the truth about the so-called 'ghost apparitions.'" Ye Yu's eyes flashed with a moment of confidence.

"Really?? Is it really someone who is doing a ghost!? Who the hell is it?? The bald man hurriedly asked.

"Don't worry, we might be able to catch this 'ghost', and we need your help in this matter." Ye Yu smiled at the bald man.

"I have a plan." ――

After dark, the campus is silent, and occasionally a wild cat burrows through the grass, stirring up a slight noise, and then it is quiet again. The low clouds hide the moonlight, making the surrounding scenery seem to be covered with a layer of black fog, which seems to be a little chaotic.

And under the cover of this night, a dark shadow quietly crossed by.

At this time, all the attention of the security guard on duty in the guard room was focused on the adult video on the mobile phone screen, and he didn't notice the fleeting figure.

The figure looked around vigilantly, and after confirming that no one was there, quietly infiltrated the school building.

Enter the door, go upstairs, step into the hallway. The figure's movements didn't stop for a moment, and its target seemed obvious—the lecture hall at the end of the corridor on the second floor.

With the dim emergency light in the hallway, the figure slowly walked to the door of the lecture hall, hesitated for a moment, and then reached out and gently pushed the door of the classroom as if he had made up his mind.

"Squeak-"

With a soft sound, the door of the lecture hall opened, and it turned out that the door did not seem to be locked at this time.

The figure breathed a sigh of relief, moved his hand to the wildly beating chest, and after taking a few deep breaths, he finally took out a WeChat flashlight, bent his waist, and tiptoed into the lecture hall.

The dazzling "blood letter" was still silently "stationed" on the snow-white wall of the classroom, and under the light of the flashlight, it showed an extremely strange visual effect.

The figure stood still in the classroom, silently staring at the cursed words on the wall in the faint light of the flashlight.

"Hmph...... Deserve! ”

A cold voice sounded faintly, and the figure gritted its teeth, its body trembling slightly, as if it was trying to restrain its emotions. But soon, the figure came back to his senses and shook his head slightly, as if remembering the purpose of his visit.

The figure walked up the stairs, counting the rows of desks in the classroom by the light of a flashlight, and finally stood still in a position near the aisle.

The figure leaned down and snooped his flashlight under his desk.

"It's okay, it's still ......"

The figure seemed relieved, and immediately reached out and removed a thumb-sized square box that was glued to the bottom of the desk.

The figure looked closely at the box in his hand, and after finding that it was not damaged, carefully placed it in the pocket of his clothes, then got up, followed his memory, walked to the desk in the other hallway, and leaned down again to look under the desk.

This time, however, the figure didn't see the object he had expected to exist under the desk.

"Strange, I'm obviously ......"

The figure seemed to be a little flustered, and quickly got up and walked to the other adjacent desks to check them one by one, but the result made it more and more panicked.

"No...... Why is there no more?? ”

The figure's voice was visibly panicked, but it persevered, and simply probed the desks of the entire classroom one by one, but found nothing.

"Impossible! Did anyone take it? No, who would find out about this ......"

"Are you looking for this?"

Just as the figure was at a loss, an abrupt voice suddenly sounded. Before anyone could react, the lights in the classroom turned on instantly, illuminating the originally dark room at a glance.

"Is this what you want to recycle?"

Ye Yu said, walking into the lecture hall, holding a thumb-sized black metal box in his hand, and this thing was exactly the same as the figure that the figure had taken out from under the desk.

"Haha, I was fooled, it seems that the 'Waiting for the Rabbit Plan' you mentioned yesterday was very successful." The sweet voice floated with the two figures who followed, and I saw Xiaolu and the bald head of the security section also walk into the classroom together.

"Oh, because I'm sure he'll come back and get these things back." Ye Yu looked at the handsome boy in the center of the classroom, raised the metal box in his hand, and smiled softly. "That's why I asked the head of the security section to deliberately release the news that 'the door lock of the lecture hall is broken', just to let him show up, and he really lived up to my hard work."

Ye Yu said, gradually putting away his smile.

"Your 'ghost farce' was a success, but unfortunately it fell short...... What do you think of it yourself? Liu Ziheng. (To be continued.) )