Yin Feng was slightly annoyed at being interrupted. His cheeks puffed up with air like a round bun before he let out a “puff.”

You Mingxu felt better—this version of Yin Feng was more pleasant to look at.

He continued, “These two cases seem completely unrelated. But thinking carefully, they have several similarities.”

You Mingxu raised an eyebrow, her interest piqued by his words. She crossed her arms, thought for a moment, and took the lead: “First, neither case has a suspect.”

Yin Feng squinted as he smiled, looking like a sweet big cat. Yet combined with his tall, sturdy frame and handsome, defined features, it created another instance of his seemingly split personality.

He responded, “Yes, those with motives had no time, those with time had no motives.”

You Mingxu pondered his words internally, feeling her heart flutter slightly with an inexplicable sensation.

“Continue,” Yin Feng said.

You Mingxu nodded, about to continue, when she suddenly realized his commanding tone. Seeing his casual expression, You Mingxu let out a light snort and kicked him in the waist. He froze, holding his waist while looking at her with wounded eyes: “Axu, why did you kick me?”

“I kick when I want to, what can you do about it?”

He widened his eyes, showing an expression of indignation but not daring to speak, only stepping aside to dodge.

You Mingxu felt instantly satisfied, her eyes sparkling as she continued her conclusions: “Second, both killers were familiar with the victims’ habits and routines, and knew the surroundings well; third, both were disguised as crude robbery-murders; fourth, the killers went straight for murder, using brutal methods, full of hatred.”

Yin Feng mumbled, “Isn’t the fourth point what I’ve been emphasizing all along?”

You Mingxu glanced at him, and he immediately shrank away again. But You Mingxu was satisfied once she’d had her fun bullying him, and with a half-smile, she lightly kicked him again, saying, “Big sister’s finished, what insights does our handsome boy have?”

Yin Feng wasn’t stupid; he could sense the gentleness in this kick, which suddenly made his mind fuzzy as if touching something yet nothing at all. He shook his head to clear it, while You Mingxu watching from the side just thought he was being silly again.

Then he said: “There are two more commonalities. First, although the victims differed in gender and occupation, they both held dominant and controlling positions in their local interpersonal circles. Second, in each case, there was a teenager who entered a new environment, faced comprehensive pressure, couldn’t gain identity recognition, and lived under the victim’s dominant influence. I think their psychological states must have been very similar: confused, suffering, tormented, lonely, and filled with intense… resentment.”

Yin Feng’s words made You Mingxu uncomfortable. She said coldly, “That was his aunt and his cousins!”

Yin Feng just looked at her with clear eyes.

You Mingxu said, “It’s all just your speculation, there’s no evidence they conspired. They’re just children!”

Yin Feng said, “There is evidence. The footprints at Xie Huifang’s crime scene were size 39, and the bloody footprints in Xu Jiayuan’s case were size 38. What are the two children’s shoe sizes?”

You Mingxu remained silent.

They had recorded everyone’s shoe sizes for both cases. But since the cases weren’t investigated together, no one would think in this direction. How did this person think to connect the two cases? And if she remembered correctly, Li Biran wore size 38, Liu Ruyu size 39.

“The killer in Xu Jiayuan’s case wasn’t as careful as in Xie Huifang’s case—they didn’t wear shoe covers. Just compare the bloody footprints with Li Biran’s shoe patterns, and we’ll know. Kids might not clean up thoroughly; we might find other things, like blood traces and soil from the scene.”

“I’ll check the footprints,” You Mingxu said, “But it’s still far-fetched. We can’t conclude they’re the killers just because the teenagers in both cases were in similar situations. I’d rather they weren’t the killers.”

Hearing this, Yin Feng smiled slightly and said, “Axu is soft-hearted. But if you think carefully, it’s not far-fetched at all. The two youths aren’t just in similar situations. The two cases are too similar. Though revenge killings where the perpetrators knew the victims well, final investigations point to strangers in both cases.

At this point, coincidentally, two people who just had intense conflicts with the victims have footprints matching the suspects in each other’s cases, and so coincidentally, both have shoe sizes that are small for their age group. Moreover, importantly, they both fit the criminal profile of each other’s cases. If this is a coincidence, it’s too much of a coincidence.”

You Mingxu couldn’t sit still anymore. She jumped off her chair and headed out: “I’m going to investigate now.” Yin Feng immediately followed, and at the door, he said, “Don’t go out in your sleepwear!”

If he hadn’t mentioned it, You Mingxu would have forgotten she was wearing sleepwear. She rushed into her bedroom, quickly changed clothes, and came out saying, “Let’s go.”

As they walked, You Mingxu asked, “How did you think to connect the two cases?”

Yin Feng answered: “Something Xu Jiayuan’s roommate said: he mentioned that days before the incident, Liu Ruyu went to an internet café in the city with Xu Jiayuan. There are plenty of internet cafés near the factory in town, so why specifically go to the city? I calculated that from the factory, the most convenient and closest commercial area would be the street where Li Biran frequents internet cafés. If Liu Ruyu had brought Li Biran to the factory to identify someone, there would be witnesses and evidence. But taking Xu Jiayuan to the internet café, letting Li Biran get a good look—no one would notice, right? I think Liu Ruyu must have read many detective novels, quite clever. However, the characteristic of cross-killing is that if it’s not discovered, you’ll never find clues; once seen through, evidence appears in abundance.”

You Mingxu’s mind raced. Yin Feng’s reasoning still had more assumptions than proof. But if following this line of thinking, both cases suddenly became clear! And the situations that had puzzled the police all made sense. Why did their criminal investigation experience and crime scene patterns point to familiar perpetrators, yet all suspicious acquaintances had solid alibis? Because they had exchanged murders.

She pulled out her phone:

“Fan Jia, immediately check Liu Ruyu’s whereabouts on the night of Xie Huifang’s murder.”

Fan Jia: “Eh?”

“Xu Mengshan, I remember the internet café owner mentioned that the night before Xie Huifang’s case, Li Biran came with a friend. Check the surveillance footage, I want to know who that friend was.”

Xu Mengshan: “Got it!”

The night was deep, and the two took a taxi. You Mingxu said, “To No. 3 Middle School.”

That was Li Biran’s school. Hearing this, Yin Feng nodded approvingly: “Axu thinks like me, pick the easier target first.”

You Mingxu didn’t want to deny this point. After a moment of silence, she added, “I hope these two cases aren’t like this.”

Neither of them noticed that a black sedan that had been parked outside You Mingxu’s residential complex started up in the darkness and followed them from a distance.