Initially, the emergence of mutants was entirely within human control.
Once it was confirmed they posed no threat to survival, the research value of these mutated species became a hot topic within the scientific community. Jiang Kelan and Gu Shaolou, a pair of partners who had worked together in labs since their graduate student days, received instructions from their investors to abandon their previous project—which was already in its second stage—and begin researching mutants.
When it came to choosing a species, the two spent a long time picking and choosing before finally settling on the seemingly beautiful and fragile butterfly.
Jiang Kelan’s thought was: *Butterflies have such a simple structure; we’ll finish the research in no time.*
Gu Shaolou’s thought was: *Butterflies have such a simple structure; there must be so much room for development.*
They were partners, yet they were worlds apart in their thinking. It was a miracle they had managed to tolerate each other for so many years.
The investors didn't mind their choice, though they hoped the research would lean toward practical, lifestyle applications—such as whether butterfly wings could be used as pigment components or if their scales had medicinal value.
Jiang Kelan felt this direction carried little pressure, and their progress maintained a satisfying pace. As a "corporate slave" with little ambition, he clocked out on time every day, slipping away faster than anyone else.
Gu Shaolou, however, stayed at least two hours later than him every evening. He couldn't even be moved when called for dinner.
Jiang Kelan even went so far as to inspect the lab and scrutinize the progress reports. Every milestone was achieved by the two of them together, so what was Gu Shaolou busy with behind his back?
Gu Shaolou certainly wasn't going to tell him directly, and Jiang didn't want to ask. Finally, Jiang Kelan turned his gaze toward the funding records on Gu Shaolou’s computer.
Because Jiang Kelan was lazy, the budget expenditures and the itemized lists for the investors were all handled by Gu Shaolou. One afternoon, while Gu Shaolou was out purchasing supplies, Jiang Kelan secretly sat at his computer. He easily bypassed the lock screen by entering Gu Shaolou’s birthday and found two sets of experimental expenditure records among a pile of files.
The first was normal, no different from the experimental supplies they usually consumed. But the second...
He saw that Gu Shaolou had purchased the flesh and blood of many different types of animals, specifically from various body parts.
Jiang Kelan was momentarily dazed. *Why would he buy this? Aren't the butterflies usually fed honey water...*
*Shit.*
He observed the containers used to raise the butterflies every day; there was definitely nothing wrong with them. That meant Gu Shaolou must have hidden other culture boxes somewhere in the institute. Just as Jiang Kelan was about to stand up and search the lab for Gu Shaolou’s hiding spot, a hand landed on his shoulder, preventing him from rising from the swivel chair.
The man who had claimed to be going out for supplies was now standing behind Jiang Kelan, pressing down on his shoulder.
"What are you looking for on my computer?"
***
The record in the document stopped abruptly there. Xing Yue flipped through the rest herself, confirming there were no other files on the computer to continue the story.
Xin Ye took a few photos of the screen, still mindful of recording data to upload for bonus points.
"Have you checked other places?" Xing Yue asked.
Xin Ye had specifically checked with Xun Yin regarding the time Xing Yue would wake up. "No, I was waiting for you."
Knowing Xing Yue would overthink and feel like she was a burden, Xin Ye added, "It’s not safe to go alone. Two people can look out for each other."
Xing Yue’s hand, which had been clenched into a fist on her lap, relaxed. She nodded gently.
The underground research institute was vast; exploring it together would still take considerable effort. Aside from the first room—Jiang Kelan’s private lounge where the computer was—they found butterfly eggs in almost every corner. However, these eggs were shriveled and lifeless, clearly dead.
Following the hints from the document, both set their primary target as Gu Shaolou’s lounge.
The easiest place to find was the laboratory, but it contained nothing but dust-covered equipment and discarded reports full of technical jargon. Not a single butterfly feeler could be seen in the empty culture boxes.
Xing Yue stared at one of the boxes for a long time before asking Xin Ye, "I remember you saying that the butterflies like to drink human blood, and the eggs on the Dome were cushioned by a layer of flesh? And that flesh belonged to other mutants. The document also mentioned Gu Shaolou purchasing flesh and blood. There must be a necessary connection between the two, right?"
"If I had to guess, this is the result of Gu Shaolou’s cultivation," Xin Ye said, suddenly feeling the joy of letting his imagination run wild, much like Leng Xianye had during the Sparrow Vine mission. "He changed the eating habits of the mutated butterflies, allowing the species to... evolve?"
"Jiang Kelan said the butterfly disaster originated from Gu Shaolou, and the root of that disaster was the butterflies' intellectual evolution. Their swarm leaders possess intelligence comparable to humans, and they can even use broadcasts and speak. In other words, Gu Shaolou’s research caused the butterflies to evolve intellectually?"
Xing Yue felt Xin Ye’s logic was sound, but there were still doubts. "Can such an evolution occur just by switching to a diet of flesh and blood? What kind of animal has that much power?"
Xin Ye had been thinking about this as well, and now he had the answer.
"Humans."
Xing Yue heard her own heartbeat quicken.
Xin Ye raised his hand and pulled off his left tactical glove. The scar he had carved into his hand to attract the butterflies and enter the barrier was still deep in color. "To be able to rival humans, naturally... they had to eat humans."
***
Gu Shaolou’s lounge was built in a corner, diagonally opposite Jiang Kelan’s lounge—practically a world away.
Xin Ye’s first instinct was to check the computer, but Gu Shaolou’s computer had been smashed to pieces, and there were several butterfly eggs inside the tower.
Xing Yin had no blackboard to rap on, so he tapped his laptop screen instead: [Pay attention to the lesson. Searching aimlessly is useless; you're straying from your original purpose as a worker.]
Xin Ye gave up on the computer and found several sheets of scratch paper in a drawer. They appeared to be Gu Shaolou’s initial experimental hypotheses for the evolution of the mutated butterflies. "How am I straying? Teacher, don't just criticize me—teach me."
[Forgot already? The butterflies can control your multi-functional watches and even perform broadcasts. Such equipment indicates two things: one, it’s bulky because of the high computational load; and two, it must be heavily guarded by butterflies. But you don't see anything like that here, do you?]
"You’re right," Xin Ye said, a realization dawning on him. "But the equipment should be here. Moving it long distances would easily damage it, and besides a place like this city, there’s nowhere else to find a power supply, right?"
[Of course. The advantage provided to the contestants in the early stages was the buildings—the last shelters before the disaster began. All the usable energy was left here.]
Xun Yin suddenly asked a question: [Gu Shaolou conducted his experiments behind Jiang Kelan’s back. Where do you think would be the safest place to hide things to successfully evade a carpet search by his own partner?]
The place that would arouse the least suspicion... was the place furthest from Gu Shaolou’s lounge: Jiang Kelan’s own lounge.
Xin Ye called for Xing Yue to return with him. On the way, a voice request from Leng Xianye popped up on his multi-functional watch.
After putting on the receiver, the first question from the other side was: "Is Xing Yue awake?"
Xin Ye: *Can we let Leng Xianye and Xing Yue do the next two-person mission?* This wasn't an office, but he hoped everyone would show some respect for his work.
Xun Yin: [Sorry, I'll keep that in mind for next time.]
Leng Xianye only asked that one question before cutting to the chase. "Tang Qiuqiu and I have met up with Lian Muyun. We’ve found a second entrance in a ruined building. The orientation is a bit far from you, roughly South-Southwest. This entrance looks like an emergency evacuation tunnel. Has your position changed?"
"No. We have a new discovery, so we’re returning to the starting point." Xin Ye had already led Xing Yue back to Jiang Kelan’s room. With Xun Yin’s reminder, he found a hidden door under the bed. "If you find the research institute, come to Jiang Kelan’s lounge and look for the trapdoor under the bed. The equipment the butterflies use to control the broadcasts and watches is there."
"Copy that." Leng Xianye pulled open a door nearby, and the three of them ducked into a room.
The pursuing butterflies flew straight past. For now, they didn't have the brains to realize people would hide in a room.
"Also, because Xing Yue’s Unbreaking Silk has disappeared, butterflies are entering the Flooded City in massive numbers," Leng Xianye said, his breathing slightly ragged. "A certain number of them have followed us underground. Be careful."
Xin Ye replied with an "OK," hung up, and refocused on the passage.
Xing Yue’s Unbreaking Silk had already coiled around her fingertips, and Xin Ye summoned his Mirror Image.
The stairs in the passage were stable and easy to navigate. The silk strands preceded the Mirror Image, probing into the depths of the darkness. Xin Ye stood behind the Mirror Image, hands resting on its shoulders, tilting his head to look down by the light of the flashlight in its hand. "Can you sense the mutants yet?"
The Mirror Image closed its eyes to sense for a moment, then nodded upon opening them. "Yes. Quite a few. But if they're all butterflies, we can handle it."
Soon, a pale blue light appeared ahead, along with several butterflies. They lunged forward aggressively to attack, only to be intercepted by Xing Yue’s Unbreaking Silk and shredded into pieces.
At the end of the passage was a small room.
The only object in the room was a console placed against the wall. The few remaining butterflies were perched on it, motionless as statues. Xin Ye approached the console and found the screen displaying two columns: the broadcast control system and the watch function operating system. No one was touching the buttons; the programs were running themselves.
In the bottom right corner was a small box indicating the number of remaining contestants. There had been one hundred and forty in total; now, there were only fifty-odd left.
Having not checked the elimination notices for a while, seeing the data so abruptly made Xin Ye feel a sense of unreality.
Fortunately, all five of them were still in.
"Xin Ye! Come look at this." Xing Yue stood at the far left of the console, waving him over.
He walked over, and when he saw what Xing Yue was pointing at, his heart skipped a beat.
In a corner of the console, there was a butterfly-shaped recessed area sealed with glass. Inside, lying quietly, was a butterfly riddled with wires.
A blue butterfly—identical to the one that had once lingered on Xin Ye’s shoulder.
[This one is the Core,] Xun Yin said, sounding satisfied with his plot design upon hearing Xin Ye’s slight intake of breath. [How could a machine like this function without someone constantly controlling it? So, the Core has to stay here forever.]
[Did you really think a tiny insect could possess such great wisdom? You can't think without a brain. So... every part of the mutated butterfly’s body, except for the antennae, has evolved into its brain.]
[Xin Ye, as long as you smash the glass and destroy this butterfly, the core of the mutated butterfly swarm will be destroyed. Your team will be the undisputed champions of the branch preliminary. Go for it!]
As soon as Xun Yin finished speaking, the butterflies that had been motionless on the console began to move. Together, they pressed a red button.
An opening appeared in the blank wall, and countless butterflies flew out, swarming toward Xin Ye, the Mirror Image, and Xing Yue.
***
