Hearing Guo Na say that Yu Fan had a dog nose, everyone looked at Yu Fan with strange eyes.

Guo Na continued to explain: "When I was in BJ City, I saw with my own eyes that Brother Yu could smell the composition of a chemical just by sniffing it with his nose, and push-ups were magical. ”

Chen Jiaoyang teased Yu Fan with an exaggerated smile: "Oh, I'll go, why are you so keen, you are a dog for a long time?" ”

Yu Fan smiled helplessly and ignored them. He gently picked up the phone, concentrated, and once again performed his sniffing stunt, sniffing it carefully for a while.

Everyone didn't get close to Yu Fan, for fear that some smell on their bodies would interfere with Yu Fan.

Yu Fan sniffed for a while, put down the phone, stayed for a few seconds, and then said in a slightly hesitant tone: "This should be the smell of engine oil." ”

Yu Fan picked up the phone again and sniffed it, and his tone became firmer: "This should be the smell of engine oil, the unique greasy smell of high-lubricating oil, if nothing else, the arsonist wiped off the fingerprints on the mobile phone with his clothes in a hurry, but accidentally rubbed the oil on the clothes on the mobile phone." ”

Zi Yan continued to reason: "In this way, this person is likely to be a factory worker, and the working environment he is exposed to will be stained with engine oil!" ”

Yu Fan handed over the mobile phone to Chen Wanli and said, "Wanli, can you see what clues you can find through this mobile phone?" ”

Chen Wanli took the phone, plugged in the data cable, and began to study the phone. Yu Fan turned back and asked Zi Ying: "This town is generally full of textile factories or garment factories, and the workers are generally relatively clean. And this kind of generally, only the clothes of the workers in the mechanical processing plant are easy to get a lot of engine oil, what are the mechanical processing factories in our town? ”

Zi Yan walked to the map of the town on the clue wall and snapped his hand: "There is only this one, Zhong Kefeng Machinery Factory in the east!" ”

Guo Na exclaimed in surprise: "Then let's go directly to this machinery factory, maybe we will find something?" ”

Chen Jieyang looked at his watch: "It's only four o'clock now, we will definitely be able to catch up before we get off work in the past, and we will definitely be able to find any clues." ”

Yu Fan was not in a hurry, he asked Chen Wanli: "Wanli, how is it?" Did you find anything about this phone? ”

Chen Wanli kept fiddling with the mouse and keyboard, and said with some frustration: "This is a whiteboard phone, which means that it is a formatted phone." SIM cards are also black cards. In this mobile phone, except for broadcasting calls to us, there is no other operation. ”

Yu Fan lowered his head and pondered, and muttered silently: "It seems that this arsonist has a strong anti-reconnaissance ability and is also very rigorous in doing things, this time we are startling, next time he will definitely be more cautious, and it will be more difficult for us to catch him." ”

Chen Jiaoyang: "Then quickly cut through the mess, let's go directly to the machinery factory, see what tricks this kid can play, and when he is not ready, give him a surprise first!" That tech otaku. The headset is on, and if there is anything new, you can contact the headset directly. ”

Yu Fan nodded, let's go and see it first, Yu Fan, Chen Jiaoyang, Guo Na, and Zi Yin rushed to Zhong Kefeng Machinery Factory non-stop. I have to say that with Chen Wanli's joining, many things are much easier.

Today has been in the middle of the gallop, Yu Fan knows the importance of time, wait for a minute and a second, the more danger this town will be. If it's an ordinary offender, they will relent when they learn that the police are searching for them, but for a psychopathic serial arsonist, knowing that the police are looking for him will only stimulate him to commit crimes faster. The demon in his heart knows that his carrier has been exposed, so he will squeeze the last ray of value out of this empty person faster!

Zhong Kefeng Machinery Factory arrived. The four soldiers divided into two routes, Chen Jieyang and Zi Yan went to find the person in charge of the factory to understand the situation, while Yu Fan took Guo Na straight to their raw material warehouse.

Guo Na was actually confused, and she asked Yu Fan suspiciously: "Brother Yu, why do we want to go to the warehouse?" Shouldn't we go to someone? ”

Yu Fan said while trotting: "It's too late to explain, I want to confirm something!" ”

When the warehouse arrived, under the leadership of the warehouse keeper, Yu Fan and Guo Na entered the warehouse, and Yu Fan went straight to the oil area. There are about 20 large iron drums of 200L stacked in the oil area, with everything, cutting fluid, lubricating oil, anti-rust oil and so on.

Yu Fan observed carefully, walked around, and asked the warehouse keeper next to him: "All the oil products are here?" ”

The warehouse keeper nodded: "All the oil products are here, and all the oil products are directly put into storage." ”

Yu Fan bit his lip: "Oh no, it's not here, go and tell Chen Jieyang and Ziyi." Guo Na, let's go! ”

Yu Fan ran towards the factory office area, and happened to meet Chen Xiangyang and Zi Yan coming down from the upper floor. Chen Jiayang also saw Yu Fan who came in a hurry, so he said: "Old Yu, there are about 50 workers in this factory, and this factory director is about to take us to the workshop to introduce us one by one." ”

Yu Fan stopped everyone and said to everyone: "I think, the target we are looking for is not here at all!" ”

The crowd was amazed.

Yu Fan's trotting all the way made him a little out of breath, Yu Fan took a breath and said: "There is no T321 isobutyl sulfide in the oil products in the oil depot here, and there is an obvious smell of isobutylene sulfide in the oil smell on the mobile phone." ”

Guo Na reacted immediately: "Brother Yu, just now you went to the oil depot for the first time, just to see if the oil they used here is the oil left on the mobile phone, right?" ”

Yu Fan nodded affirmatively to Guo Na and continued to explain: "T321 is a sulfur-containing additive made of sulfur or sulfur monochloride and isobutylene as raw materials. Sulfur-containing additives provide protection in metal-to-metal high-pressure contact in boundary lubrication. The extreme pressure anti-wear performance of sulfur-containing extreme pressure anti-wear agent is related to the C-S bond of sulfide, and the weaker C-S bond is easier to form a protective film and has a better anti-wear effect. At present, most of the extreme pressure anti-wear agents containing sulfide are isobutylene sulfide. ”

Guo Na added to Yu Fan: "Lubricating oils with T321 sulfide isobutylene generally have stronger lubricating performance, and their application scenarios are generally gear oils, anti-wear guide oils, extreme pressure cutting oils, etc. ”

Yu Fan felt that the cooperation between himself and Guo Na was becoming more and more tacit, and Yu Fan continued to explain: "So there will be no person we are looking for here. I strongly suspect that the oil on the arsonist's clothes came into direct contact with the oil used for the equipment, not during machining, and he was not an ordinary operator! Combined with this person's previous characteristics, he has certain hands-on ability and technical ability, and I strongly suspect that he should be an equipment maintenance worker in a factory in this town! ”

Everyone's brains are racing. Yu Fan: "Guo Na, you make a list of oil varieties containing isobutylene sulfide and hand it to Zi Yttrium, and ask them to go to various factories to check which factories use these oils." ”

Chen Xiangyang was a little anxious next to him: "It's already past five o'clock now, many factories are off work, and this investigation will take a long time, what can we do, in case he arson again tonight, we have no way at all." ”

Yu Fan showed a weird smile: "Don't wait for him to set the fire, I'll help him add a fire." ”