About 40 minutes later, Conan, Chiba and the others, accompanied by Officer Nishimura, returned to the Big Dipper train.

"Do you have any opinions?" Conan asked.

"Probably a little guess," Chiba shrugged. "But I need to verify it further, after all, I don't know anything about corpses, and even if I stare at corpses like you, I can't find anything useful."

"Do you have any guesses about who the prisoner is?" Conan asked again. "If you choose from the people we've met."

"Choose from there?" Qian Yu replied after thinking for a moment. "If I had to choose one, I would choose the secretary, which is the idea that best explains the situation at that time."

"Explain the situation we were in?"

"yes," Chiba nodded. "If you didn't see anyone else at the time, the only explanation is that you hid in the staircase of the secretary and Keitaro Izumo's box. Considering that you didn't find any suspicions later, I'm afraid it's easiest for the secretary to sneak back into his room above. ”

"Where's the technique?" Conan asked.

"Don't ask me," Qian Yu immediately shook his head. "There are so many possible ways to do it, and you have to ask him what happened to find out."

"Hmm," Conan nodded. "Let's go back and re-check Box 5 and see if there are any clues in it."

As soon as he got on the train, Conan took Chiba, Officer Nishimura and the others straight to Box 5 - Dr. Asa had been waiting here for a long time, and the quilt that had been quite neat had been opened.

"You've been here?" Officer Nishimura immediately realized the abnormality of the quilt and asked.

"yes, and we found something interesting." Dr. Asa nodded, then pulled an envelope out from under his mattress. "There's something interesting on that quilt, but what's inside this envelope is actually the most important thing."

"This is ......" Officer Nishimura narrowed his eyes slightly, then reacted. A thing about Asama Yasuji? ”

"Yes," Dr. Asasa nodded. "We've already read the content, officer, you can also take a look, it explains the identity of the person who is most likely the murderer."

"What!?" Officer Nishimura was taken aback, quickly took the envelope, and then took out the letter from the opened envelope three times and two times, and looked at Dr. Asasa with a strange look twice.

"Don't be surprised," Conan seemed to know what was going on. "If nothing else, the secretary is the only person in this case."

"What is this?" Qian Yu didn't understand what was going on at all, and hurriedly asked Conan about it.

"Officer Nishimura, show them this." Conan looked at Officer Nishimura and said. Officer Nishimura immediately handed the letter and envelope to Chiha.

"......" Qian Yu took the letter, looked at the contents of it, and then immediately locked his brows. This ......"

The letter was handwritten, letterheaded by Boss Asama, stating that the writer had booked a ticket for Asama's Hokuto train and invited him to join him in a big deal - the plan was too secret to be discussed in detail, and he could only be told the details of the plan after he came. In order to show his sincerity, he specially ordered an expensive ticket for him on the Taipei Douxing train.

And the signature at the end is...... Ka-Etsu.

"Who is Ka-Etsu?" Qian Yu asked, and Gray Hara, who was leaning next to him and reading the letter, was also confused.

"Secretary." Conan replied simply and clearly. "His name is Caviet Ritsar."

"Why is this letter here?" Qian Yu asked again. "Why is it under the mattress?"

"I don't know why," Conan shook his head. "But Dr. Asasa told me that he didn't find Asama's luggage, so I guess it's possible that the secretary threw his luggage out after killing Asama. But Asama Yasuji had long felt that the secretary's motives for inviting him to take this Big Dipper train were not pure, so he took precautions in advance and hid the letter under the mattress. Of course, this is my personal suspicion, and the only one who really knows the reason is Asama Yasuharu himself, and this reason has become an eternal mystery with his death. But beyond this letter, I think we need more evidence against Mr. Gaviet, for example, we may need to search all of his luggage. After all, he probably didn't have time to throw away the clothes he wore when he assassinated Keitaro Izumo by now, and he also didn't have time to dispose of the traces of gunsmoke reaction that might be on his body. ”

…………

"What are you looking for me for?" The secretary, Kagoshi, looked at Officer Nishimura suspiciously.

"Just a bite to eat," Officer Nishimura said. "It's already morning anyway, so we think you're probably hungry, so we've got something to eat for you."

"I'm ......," said Kavili, grimacing. I'm not really hungry, so I don't want to eat anything. ”

"Don't want to eat anything?" Officer Nishimura's eyes narrowed slightly. "The breakfast here is really delicious, and it's usually only available in the SA1 Royal Box, so you really don't want to experience it?"

At this moment, a policeman walked quickly from the back of the car, and then whispered a few words in Officer Nishimura's ear, and Kayue Rino could even see the change in Officer Nishimura's expression.

"Perhaps, have you already had a late-night snack?" Officer Nishimura suddenly showed a cold and warm expression. "If you've already had a late-night snack in a box with a friend, we can really understand that you don't want to eat."

"Ah......h This ......"

"After all, that's your old boss, Yasuharu Asama, and it's rude not to eat a little, isn't it?" Officer Nishimura's expression was suddenly cold in the next moment. "The murderer who killed Yasuharu Asama and Mr. Keitaro Izumo, Mr. Rinzori Kakoshi?"

"Ah......h Mr. Officer, are you kidding? You can't talk nonsense about this kind of thing! ”

"I'm not talking nonsense," Officer Nishimura sneered. "We've found the murderer's costume in your box, do you think you have anything else to quibble about, or do you think you can explain the positive result of the gunpowder smoke found on it?"