The sudden commotion startled everyone. The two security guards froze for a moment, then said excitedly, "That's the sound! We heard it once before!"
After the ripples caused by the fish tank settled, a person stood up from the water right where they were.
Inspector Megure stared at his subordinate, drenched like a drowned rat, in utter shock. "Takagi? When did you get over there?!"
Officer Takagi wiped the water from his head and lifted the fish tank. He looked at Inspector Megure, equally incredulous. "I was underwater the whole time. You really didn't see me just now?"
"That's right." Inspector Megure scratched his head, feeling as though he'd seen a ghost. "Don't tell me you secretly swam over while the fish tank was floating up?"
Officer Takagi, who had been crouching inside the overturned fish tank for ages, said, "Of course not!"
"I see." Beside them, Jodie adjusted her glasses, finally understanding. "Though water and air are both transparent, they refract light differently. When viewed from an angle nearly perpendicular to their boundary, the light is reflected back like a mirror. That's why people on shore can't see what's inside the fish tank.
"Officer Takagi was hiding inside that wide, overturned fish tank. That made him impossible to see from the poolside. The only angle from which he could be seen clearly was almost directly overhead, but this pool is quite wide. Unless someone could fly, no one could reach that angle."
As Jodie spoke, her voice gradually lowered—she noticed Jiang Xia looking at her.
For some reason, despite him clearly being a harmless high school student, Jodie felt a chill crawl up her spine under his gaze. "What is it?"
Jiang Xia shook his head. ...I suddenly realized you'd make a pretty good detective's assistant too.
Yet the