After some effort, Natsuyu finally reached a spot not far from the roller coaster entrance—just in time to see Ayumi and the others she'd met earlier. The three of them were squeezing through a small hole beside the tracks, clearly planning to sneak in and ride for free.
Before Natsuyu could stop them, the kids moved with surprising agility and slipped inside one after another.
If those three were already here, that meant Kudo Shinichi and Mouri Ran must have only just arrived as well.
Sure enough, when Natsuyu shifted her gaze to the entrance, she spotted a high school boy and girl standing in line. The boy was talking animatedly, going on and on, and mid-sentence he suddenly reached out and grabbed the girl's hand in front of him—this had to be the murderer in this case. The girl with the distinctive horn-like hairstyle, on the other hand, looked visibly displeased.
For a moment, Natsuyu couldn't think of a direct way to stop the incident. Her original plan had been to board the same roller coaster as the protagonists and deal with things as they unfolded. Even if she couldn't prevent the crime, at least she'd be able to gather firsthand details, which would make solving the case more convincing.
But just as she was about to act, a thought struck her—
There were no extra seats left on that roller coaster.
Eight seats total. Kudo Shinichi and Mouri Ran took two. The victim and his companion—one of the three suspects—took four. And Gin and Vodka, appearing for the first time, occupied the remaining two. Not a single seat was left.
At that moment, Natsuyu glanced toward the small hole Ayumi and the others had crawled through earlier. Recalling the relevant plot details, an idea formed in her mind.
She turned and walked over to the hole, and while no one was paying attention, she slipped inside as well.
Earlier, when washing her hands, Natsuyu had seen her reflection. Her appearance was remarkably similar to the Traveler, Lumine, from the game—just a few years older-looking. She could barely pass as an adult, and her athletic ability was quite good. Crawling through the hole was quick and effortless.
Inside, it was pitch-dark. As expected, Natsuyu realized her night vision was excellent—she could clearly make out her surroundings.
After moving forward for a short while, she soon heard children's voices ahead.
"Ayumi, is that you?" Natsuyu called out. She saw the three children ahead freeze mid-step; they'd been about to run when they heard footsteps.
"It's that big sister from earlier!" Ayumi exclaimed happily.
Ayumi looked back at her. "Big sister, why are you here?"
Of course, Natsuyu couldn't tell them her true purpose. Fortunately, she'd already come up with an excuse.
"I saw the three of you crawl into this hole earlier and got worried, so I followed you in."
She also took the opportunity to stall for time and gently lecture them. In the story, these kids were always reckless—bold to the point of being careless, daring to squeeze into places they really shouldn't.
Natsuyu crouched down and spoke seriously, "Do you know how dangerous this is? Right next to us is the roller coaster track. What if the coaster comes through and you don't have time to dodge? What if it hits you?"
Ayumi and the others exchanged uneasy looks, then lowered their heads, obediently admitting their mistake.
Seeing how well-behaved they were, Natsuyu wasn't sure how much of it had truly sunk in. They hadn't known each other long, so she didn't press further.
She gently patted their heads, then stood up. "Alright. It's too dark in here—don't stay inside. Hold my hand, I'll take you out."
Just then, Natsuyu finally heard the rumble of the roller coaster approaching the tunnel. At the same time, Paimon warned her:
[Traveler, the roller coaster is almost here!]
Natsuyu grabbed Ayumi's hand and pulled her to the side. With her other arm, she shielded Mitsuhiko and Genta, guiding them to press closer to the wall.
"Careful—move to the side. The roller coaster is coming."
"Whoosh—"
The coaster roared past, rushing through the tunnel and disappearing moments later.
Almost immediately, Natsuyu caught a faint metallic scent of blood in the air.
"Da—da—"
She then heard the sound of something dropping onto the ground.
Ayumi felt something roll against her foot. She bent down and picked it up—it was a pearl.
When Natsuyu saw the pearl in Ayumi's hand, she knew she hadn't guessed wrong. It was most likely one of the pearls from the necklace the killer had used during the crime.
She didn't linger in the tunnel. Now that the incident had already occurred, the next step was to expose the murderer.
Once they exited the tunnel, just as expected, a crowd had already gathered around something nearby. Fragments of hushed voices drifted through the air—
"That's terrifying…"
"…the head is gone…"
(Some details here differ slightly from the original work.)
At that moment, a high school boy suddenly appeared and stopped them. Ayumi recognized him immediately and ran up to him, shouting, "Are you the high school detective?!"
The boy crouched down and introduced himself, "My name is Kudo Shinichi."
Natsuyu took the chance to study what Conan looked like before shrinking. A confident smile rested on his face; he seemed perfectly at ease being the center of attention. His guard was low, and he looked like someone who had never really suffered setbacks—someone prone to overlooking anything that didn't interest him.
So this is Kudo Shinichi…
Natsuyu couldn't help thinking that the current Shinichi was confident to the point of being slightly arrogant. No wonder he would stumble so hard later on.
As Shinichi questioned Ayumi and the others about what had happened inside the tunnel, Natsuyu stepped forward.
"Excuse me—may I ask what just happened? I heard there was some kind of incident."
Shinichi looked up at the girl in front of him and froze for a brief moment. It was the first time he'd ever seen such a beautiful blonde girl. He gave her a rough explanation of what had occurred and was about to continue questioning her when she spoke again:
"If what you said is correct, then I think I know who the murderer is."
"Huh?" Shinichi stared at her in shock. "How do you know? Who is it?"
"You said you were sitting in front of the victim, right? Then the killer is the person seated in front of you on the roller coaster. When the murder happened, Ayumi and the others and I were inside the tunnel."
Natsuyu continued, a little embarrassed, "My night vision is pretty good. When the coaster passed through, I saw someone in the first row lean over the second row and do something to a person in the third row. Combined with the pearl Ayumi found in the tunnel, it's clear the killer acted at that moment."
Just then, the police—who had received the report—arrived on the scene.
A police officer wearing a brown round hat and a matching uniform spotted them and spoke up immediately, "Kudo, you're here too?"
"Officer Megure," Shinichi greeted him. "This young lady says she witnessed the murder."
Shinichi felt a bit frustrated. After hearing Natsuyu describe the killer's position and roughly explain the method, he had already pieced together the trick himself. But having the answer spoiled in advance—without unraveling it step by step on his own—was deeply unsatisfying. A sense of emptiness washed over him, and he barely had the motivation to personally reveal the truth to Officer Megure.
When Megure heard there was an eyewitness, he was overjoyed.
Natsuyu repeated her account once more. Megure already knew the seating arrangement on the roller coaster, and after hearing her explanation, he immediately identified the culprit.
At that point, Shinichi finally refocused and supplemented the method of the crime.
He walked up to the murderer—Hitomi—and questioned her directly.
"Then, could you explain what you were doing in the tunnel, and the pearl necklace on your chest?"
Hitomi had no answer. She covered her face and broke down in tears, confessing her reason for committing the crime.
While everyone was listening intently, Natsuyu quietly slipped away. She had no intention of being dragged to the police station afterward to give a formal statement.