Eric and Chiko return to their rooms, followed by Scott. Scott felt like he had been fooled, but he still maintained a standard of service smile: "Mr. Detective, there are 25 minutes left." ”

Eric stood up and sat Scott in his place, he took the tablet from Catelyn's hand and said in a confident tone, "Mr. Scott, as I said, the truth will tell you the answer itself. Scott saw a 16x16 photo album on the screen of the tablet, and the photos of each compartment seemed to be a scene in the standard compartment of the carriage.

Scott suddenly realized: "You asked me to lock room 303 and let people stay in the room, just so that this lady can go to collect evidence." But - how did you open the rooms, each room has a lock, and only the passengers in the room can open it with an electronic proximity card. ”

"It doesn't matter, does it?" said Caitlin with a shallow smile. Scott had already regretted that he shouldn't have trusted the detective, but he was now riding a tiger. Without a reasonable outcome, he could already imagine that it would not be long before several letters of complaint from Bai Huahua would appear on his boss's desk on time.

"First of all, let's solve the first question, why the smoke alarm in room 303 did not give a warning in time. Eric clicked on the first photo, "This is what I took on the spot, is Mr. Scott familiar with this thing?" ”

Scott looked at the picture on the screen seriously: "It's like 4 burnt paperclips." Is there anything strange about this? The deceased was a professor, and many unwritten manuscripts are fixed with paper clips, so it's not strange to have these in the room. ”

Caitlyn seemed prepared. She took out a nylon bag, cut out a square with scissors, and then fastened 4 paper clips of about the same size to the four corners of the square, and used a solid glue to apply evenly to the four sides of the square. Chiko then picked up Caitlin, who sealed the nylon square with the smoke alarm.

"Simple, isn't it?" said Eric, looking at Scott, who was stunned.

Scott was still puzzled: "It doesn't make sense, Mr. Detective, it's just nonsense. ”

"It makes perfect sense, Mr. Scott. Eric retorted with a smile.

Scott felt that he was being taken for a fool, and he restrained his irritation and pointed out the absurdity of the way Caitlin demonstrated: "First, Mr. Detective, the carriage is sealed, how did this nylon paper fall off on its own after the fire?

"You're right, it just threw itself into the fire. Eric laughed teasingly, "Actually, it's very simple. With that, he tossed the bottle of solid glue to Scott. Scott opened the lid and looked up and down, but still didn't see anything recognizable. He frowned and asked, "Is there anything special?"

"This is a solid glue with malt powder as the main ingredient, and as long as it is heated to 50 degrees, it will become a paste, and it is basically not sticky. "When a fire breaks out and the room is closed, the temperature in the room is bound to exceed the normal value, and it is very easy to reach 50 degrees. ”

Scott still doesn't seem to believe it: "So how do you get this nylon paper to fall into the fire accurately and not float somewhere else?" As soon as he finished speaking, Scott noticed the paper clips at the four corners of the nylon paper, and his eyes suddenly widened as if he were empowered.

"I'm sure you've noticed that nylon paper is light and thin, and it's very likely to fall to a place where there is no fire, so as long as you find that nylon paper, the murderer's method can be easily cracked. But as long as you fasten four paper clips to the four corners of the nylon paper, then when the nylon paper comes off, the gravity of these four paper clips can make the nylon paper fall exactly below the smoke alarm. As he spoke, Eric switched to another photo, from which it was evident that there was a large scorched mark underneath the smoke alarm, similar in size to Professor Lucio, who was the first scene of the arson.

"The next step is to plug the crack in the door with a damp cloth and create a perfectly enclosed burning space. Eric flipped to another photo, and there were apparently some water stains at the bottom of the door towards the side of the hallway.

Scott looked at the photo in amazement, and then at the nylon paper in Caitlin's hand incredulously, as if he still didn't want to believe such a strange technique: "So, how do you explain that Professor Lucio was burned to death, but no one around him heard the movement?"

Eric shook his finger at Scott and said, "Professor Lucio wasn't burned, he was killed and then set on fire. The evidence is twofold. The first is circumstantial evidence, even if Professor Lucio is stunned, the power of the * medicine will never be able to offset the pain of burning himself. The second is direct evidence, but in every burned corpse, there will be burning soot in the mouth, and after death, the oral saliva secretion stops, and the soot appears dry powder. If you die by burning your body before death, your mouth will still secrete saliva, and the inhaled soot will mix with your saliva, so that the soot in your mouth will be mushy after death. I've looked at Professor Lucio's mouth and his condition is clearly dry powder. ”

Scott snorted for a moment, still not quite understanding. He asked, "But how did the murderer kill Professor Lucio without moving, and still be able to escape after arson, knowing that Professor Lucio's body was against the door, and when Bob rushed into the door, there was no one else in the room." ”

"Remember that ribbon trail?" Erik switched to another photo, "just bend a piece of thread in two, first through Lucio's waist belt and then through the crack in the door." After setting the fire, close the door and pull the corpse with a thread from the outside, we can pull Professor Lucio's distraction down the door, and then the thread will be pulled away again, and Professor Lucio's body will be burned by the fire, and by the time we find the body, the traces of the thread will have already been burned by the flames. ”

"There are two deadly problems here, Mr. Detective. Scott was a little excited, "Excuse me, Professor Lucio's body was set on fire after his death, so how can the murderer ensure that the thread used to make the secret room murder is not burned, and at the same time how can he ensure that the nylon paper can be dragged after it falls on the burning corpse? Otherwise, if the murderer pulls the corpse outside the door prematurely, and the nylon paper does not fall onto the corpse, then his methods can be easily debunked." ”

"Mr. Scott, your understanding of the line is too narrow. Eric raised his eyebrows triumphantly, "What if this thread is not the silk thread we usually understand, but a very thin wire?" If the required wire is too long to attract attention, just a small piece of wire, fold it in half and pass it through the corpse, then tie the ordinary silk thread at both ends of the folded wire, and finally hide the ordinary silk thread under the carpet in the carriage corridor, so that you don't know it." After hearing this, Qianzi also suddenly realized that there was nothing wrong, even if the fire at the scene of the crime was a little bigger, it was impossible to burn the steel wire, and the steel wire was easy to bend and deform.

Eric went on to explain: "And the question of timing of pulling the corpse is even simpler. When the fire alarm goes off, he only needs to be the first to show up at the scene. ”

Scott stared at Eric in disbelief and asked, "What do you mean—yes—Bob?" Eric shrugged his shoulders, his expression already giving an unequivocal answer.