"I'll go in first, and if there are no problems, I'll let you in twenty seconds."

Standing at the door of Yoshiyuki Kono's house, opening the door to the apartment with the key he had retrieved from Yoshiyuki Kono, Gregory turned around and said solemnly to Chiba and Ashbara.

"So there's still danger here?" The corners of Chiha's mouth twitched.

"The large dose of poison gas is definitely gone," Grigory said as he walked into the apartment. "The windows of their house are open - combined with the fact that Yoshiyuki Kono has been arrested, and his wife has been admitted to the hospital for poisoning symptoms before, so it must have been ventilated for more than five hours - the poison gas is heavier than the air, so since the policeman who stayed downstairs is still alive, it means that even if Yoshiyuki Kono opened some poison gas valve or something like that before leaving, the amount of poison gas here will not be particularly high."

"Then you're still covering us so tightly...... Qian Yu said, stretching out the hand that had been in his pocket all along—a pair of plastic gloves with elastic bands around the cuffs. And I'm going to have to wear clothes like that inside......"

Although on the surface, it seems that Qian Yu is only wearing a gas mask, in fact, he is already wearing a protective suit all over his body - an airtight protective suit from head to toe, and even if there is really any residue of sarin, he will be isolated from the protective suit.

"If you were my assistant, I wouldn't have prepared this for you." Grigory replied. "After all, those assistants have signed life and death certificates."

"Uh......" Qianyu was speechless. Although you made the clothes that Gray Hara and I wore very uncomfortable...... But I suddenly felt like I was still dressed ......"

"It's good to know." Grigory said. "Well—it's been twenty seconds now, come in."

Yoshiyuki Kono's home.

"Nothing strange looks like," Grigory said, surveying the room. "What about you?"

"If you consider that there are a lot of working people who don't like to tidy up their houses, so there will be a lot of messy places......" Chiba said as she stood in Yoshiyuki Kono's bedroom, frowning. There's nothing out of the ordinary, it's just bad. ”

At this moment, Qian Yu suddenly heard something restless-sounding from the toilet belonging to this bedroom.

"Oh!" Then, Gray Yuan's whisper of exclamation came.

"What's wrong?" Qianyu hurriedly ran to the toilet, only to find that Gray Yuan Ai had already retreated from the toilet, and there was no panic in her expression.

Looking into the toilet, Chiba found that the lid of the drain had been opened, and a small pool of liquid was boiling outside the hole in the drain, making a "crackling" sound.

"What did you do?" Qian Yu was stunned.

"It was kitchen cleaner that he put in a toilet with corroded iron sewer pipes," Gray Hara replied. "You're giving me a reason not to be curious."

"Kitchen cleaner?" Qian Yu was stunned. "Are you sure it's a kitchen cleaner?"

"yes," Graybara shrugged. "That's why I just poured a little bit, and that's it."

"Tsk......" Qian Yu looked at the sewer and pouted.

Kitchen cleaner is used to treat kitchen stains, and kitchen stains are basically acidic substances based on grease, so kitchen cleaner is an alkaline cleaner. Generally speaking, toilet cleaners are faced with alkaline stains, so they are generally acidic. However, because strong acidic cleaners can damage pure iron sewers, alkaline cleaners are sometimes used to treat toilet drains.

But if an eye damage occurs in a drain that uses an alkaline cleaner, consider whether someone has only recently started cleaning the drain with an alkaline cleaner.

"Have you found any new pesticides over there?" Just then, Grigory walked over. "Uh...... It's working time, not flirting time. ”

"Mr. Yoshiyuki Kono recently changed the alkaline cleaner to clean the drains," says Ashbara. "Maybe he poured in the undiscovered part of the organophosphorus pesticide that he had found before, so he had to use alkaline detergent to stop us from tearing down the floor and inspecting the sewer walls to find the possibility of other kinds of pesticides remaining on it."

"Don't think about that yet," replied Grigory. "There's no sealable container made of copper, lead, wax, plastic, or anything like that, so it's easier to hide pesticides than to hide them."

The reaction process of sarin gas is quite complicated - not because the reaction process of sarin gas is complicated, but because it is difficult to get the pre-materials without a backstage.

First, phosphorus trichloride can be obtained by reacting chlorine with excess phosphorus; Chloromethanol plus methanol that can be bought everywhere can be reacted to obtain dimethyl phosphite, and monomethyl methyl phosphite can be obtained after heating; Phosphorus oxydichloride can be obtained by reacting with phosphorus trichloride and chlorine gas; After that, hydrofluoric acid and phosphorus methyloxydichloride generated by the reaction of calcium fluoride and concentrated sulfuric acid are metabolized to obtain phosphorus methyloxydifluoride; Isopropyl methofronate can be obtained by adding isopropanol and phosphorus methyloxydichloride again.

In this process, there is a step that has quite strict requirements for the container - in the process of calcium fluoride plus concentrated sulfuric acid to produce calcium sulfate and hydrofluoric acid, there are special attention to the reaction vessel and the collection vessel.

The reaction vessel must be constructed of a relatively inert material that is reactive after hydrogen, otherwise the reactants will react with the reaction vessel. The collection container must be made of metal or wax or plastic that is mobile behind the fluorine. (Considering the psychology of normal people, copper is generally used as a reaction vessel and lead as a collection vessel when storing this dangerous substance.) ）

However, there are no such containers – especially no sealable containers that can be used to collect hydrofluoric acid. If Yoshiyuki Kono disposed of the containers, why didn't he dispose of the pesticides that were obviously more visible?

"In other words, there are no production conditions here?" Gray Yuan said with his hands on his chest.

"I don't think he has the production capacity," Grigory replied. "Any laboratory that can produce sarin safely, even after it has been destroyed, is in better conditions than it can be here. And although he has a lot of pesticides here, there are not many that can really be used, and I doubt that the dose found here can produce enough sarin gas to kill in the open field. ”

By this point, Grigory had already walked out. "Let's go back, there's basically no particularly valuable information here."