"You guessed correctly! Xu Fa really intends to kill people indiscriminately!" Lin Dongxue said in surprise.

"This conversation happened two days ago..." Chen Shi looked around. "Could it be that Xu Fa still lives here?"

"Let me call for reinforcements!"

Chen Shi looked at the chat log and fell into deep thought. He said, "Little Worm, look at what else has been deleted."

"Okay."

Sun Zhen created a document folder and restored the deleted things into the folder one by one. He said, "Although this person is a chemistry expert, he isn’t a computer expert. The deletion wasn’t professional at all. If you really want to delete these things without them ever being recovered, you should fill the hard drive with trash after deleting the documents and then delete them again."

"Fortunately, you didn't teach this at the time." Chen Shi whispered, lest Lin Dongxue, who was making a call at the door, heard it.

"This isn’t a high-level technique. There’s nothing to teach... By the way, since we’re dealing with Xu Fa this time, I will ask Miss Gu and kk to help too! We’ve agreed to deal with 'old friends' together."

kk said from beyond the screen, "You just want to see Sister Gu! She has a boyfriend and you’re still thinking about her, isn’t that considered improper?

Sun Zhen replied, "Get lost!"

Chen Shi said, "Gu You doesn’t need to come over since she can’t help. Get kk to stand by. Maybe we’ll find a use for him!"

There were several web pages in the recovered files. Chen Shi clicked on them and found that it was a college website. He searched for the name of the second victim and found it. Could this be Xu Fa's way of searching for "prey"?

Even if it was indiscriminate murder, he would still choose the target first and make sure that there are no unstable factors around them that could interfere. He was really cautious.

Chen Shi wanted to guess who Xu Fa's next target was from this, but he had browsed too many pages and Chen Shi didn’t know where to start.

Chen Shi wrote down all the people with specific addresses he could find. On the map, the place where the second case had occurred was five kilometers away. According to the hypothesis in criminal geography, the next crime should be no further than ten kilometers away, but this scope was still too big.

The college was a good place. There are almost no people around at night. After killing someone, you could leave their body outside and retreat.

What would I do if I were Xu Fa? Chen Shi pondered.

"Who had the second victim contacted before his death?" Chen Shi asked.

Lin Dongxue went through the chat log of the task force group and answered, "An unknown number that we couldn’t track down. They only talked for one minute."

"Xu Fa will make an appointment with the victim in advance and lure them to a place where it would be easy to take action..." Chen Shi pointed to the screen. "From now on, monitor the phones of these people!"

"How can we do that?"

"We’ll just need their consent. I think they’ll cooperate." Then he said to Sun Zhen, "Come over, we need your help!"

Afterwards, the police rushed over and the house was left for them to monitor, in case Xu Fa returned. Sun Zhen and kk met with Chen Shi at the bureau. kk was still a little nervous when he saw a bunch of police officers. Facing Lin Qiupu’s question, Chen Shi answered, "They are friends of mine."

"Informants?"

"I’ve already said they’re friends! Good buddies!"

Lin Qiupu glanced suspiciously at the two of them. They didn’t look very respectable and he wondered where Chen Shi had met people of all sorts.

For those potential targets, the police contacted them and said that they wished to monitor their mobile phones. Most of them were willing to cooperate, but a few were unwilling. So the police visited them and patiently tried to persuade them.

Taking advantage of this time and with a little effort, Sun Zhen had already written a monitoring software for each person to install on their mobile phones, so that their calls and text messages would be fed back to the police in real-time. The police promised them that their privacy would be kept absolutely confidential.

This skill garnered the admiration of Lin Qiupu. Although he felt that this was an unconventional gambit, he had to admit that it was also the most likely way to find Xu Fa.

The monitoring process was extremely boring. Everyone sat in the conference room with headphones on their ears and ate instant noodles whenever they were hungry. Most of them were male police officers, who smoked as they sat there. Lin Dongxue stood up and turned on the air conditioner. The chilly wind blew on them and some police officers tactfully put out their cigarettes.

Lin Dongxue sat down and whispered to Chen Shi, "When I become the captain, there will be a total ban on smoking in the team. What's wrong with all of them?"

"A modern Lin Zexu. I admire that!"[1] Chen Shi said.

Lin Dongxue's gaze fell on kk. He was still holding a cigar shamelessly in his mouth, and said with a smile, "Sister-in-Law, can I be an exception? This doesn’t produce much smoke."

"Go and smoke it outside! Also, call me ‘Officer Lin’!"

"Hey!" Old Zhang put down his earphones, "A suspicious courier just asked this person to go down and pick up a parcel!"

"Who?" Lin Qiupu asked.

"An unemployed young man living alone..." Before he finished, the young man called and they turned on the speakerphone. The young man said, "Police officers, you guys guessed it correctly. Someone is targeting me. I didn't buy anything but a courier suddenly asked me to go down in the middle of the night, saying something about fruit and how they would rot if I didn’t take them... What should I do now?!"

"Stall for time. Stall for as long as possible. We will head there now!" With that, everyone got ready to leave.

They rushed all the way to the scene. Everyone left their cars outside the housing district and went on foot. There was no sign of Xu Fa around. There was only one courier in yellow clothes. Old Zhang called the young man. "Call them back!"

Sure enough, it was the courier who answered the call. Lin Qiupu suspected that he might be Xu Fa's subordinate, and gestured for the courier to be arrested.

The crowd rushed up and apprehended the courier. Upon inspection, it was discovered that there was really a box of durians in his vehicle. The courier was very innocent and asked, "Why did you apprehend me? What did I do?"

Old Zhang glanced at the order receipt and called the young man, "Who is XX?"

"Ah, my dad had sent it. Sorry, sorry!"

The young man came down to take the fruit very guilty, and said that he wanted to invite everyone to eat them. Although it was a false alarm, the police felt a bit disappointed.

At this time, Sun Zhen called and said, "Brother Chen, there was a suspicious call just now. I suspect it’s Xu Fa. I will send you the target’s number and address... kk is already on the way there."

Everyone got into their cars quickly, and Chen Shi called the target on the road. The other party was a girl. She said, "Police, please quickly save me. Just now, someone said that she was Zhang X from my hometown and asked me to head down. The number is hers, but I felt that something was wrong and called Zhang X. She never came to our school at all!"

"Can you see that person?"

"There is a man downstairs, it seems..." The girl lowered her voice. "What should I do?"

"Is there anyone in the dormitory?"

"There is!"

"Don't do anything. Don't leave the dormitory. If he calls you again, say that you’re getting dressed and will come down immediately."

That school is five minutes away. Chen Shi thought. We can make it in time!

Three minutes later, the girl called back. "He’s gone!"

Chen Shi’s heart thumped. Xu Fa was very vigilant. The girl was talking on the phone just now while looking down. He had probably noticed something was wrong. Once he realized the danger, he might inject the poison into another person, so that there’d be no evidence.

The poison that cannot be detected only had value as legal evidence if they managed to obtain it!

1. Lin Zexu was a Qing dynasty official whose opposition to the opium trade sparked the First Opium War.