It was clear Kogoro Mouri, inspired by Hayashi Shuichi's success in solving the swimming pool murder case and earning Inspector Samezaki's praise, wanted to emulate him.
After all, his dream was to join the Metropolitan Police Department's First Investigation Division as a detective.
"Tell us," Inspector Samezaki said with an encouraging smile.
"All three have hand injuries, but only Keiko Kawamura's injury, on her palm, happened before arriving at the apartment," Kogoro said proudly.
"When she opened the box to steal the ring, her wound must've touched it. If we find blood on the box, doesn't that prove she's the thief?"
Silence fell as everyone stared at Kogoro.
"Well, are you all stunned by my brilliance?" he grinned.
"I'm stunned, alright," Eri Kisaki said, exasperated. "I thought you were just dumb, but this is a new low."
"If you want to be a police officer," Inspector Samezaki muttered, "I hope you're not assigned to the First Division."
"Did I get it wrong?" Kogoro scratched his head.
"We checked the box," Officer Megure said. "No blood."
"Oh?" Kogoro smiled awkwardly. "Still, I helped, right? At least it proves Keiko Kawamura isn't the thief."
"First, only her left hand is injured," Officer Matsumoto snapped. "Second, the box can be opened with one hand! Got it?"
"I see…" Kogoro mumbled, embarrassed.
As his friend, Shuichi stepped in to shift the focus. "The talisman paper on the box is yellowed. Has it been used for a long time?"
"Over forty years," Rina Hase said uncertainly.
"How do you attach the talisman to the box?"
"With paste," Rina replied. "Weren't talismans always stuck on like that?"
"Paste…" Shuichi's eyes flickered. "After showing the ring, did you immediately glue the talisman back on?"
"Of course," Rina nodded confidently. "The ring's cursed. If I don't seal it with the talisman, I'll be cursed."
Shuichi examined the talisman and noticed the paste beneath hadn't fully dried.
"Ms. Hase, did you make the paste alone, or did someone help?"
"I made it myself," Rina said. "I applied the talisman in my bedroom, alone."
Suddenly, Keiko Kawamura said darkly, "You nearly fell to your death just now. Doesn't that mean the curse got you?"
"Maybe you're the thief, framing us to extort money!"
"Curse?" Rina gasped, then retorted angrily, "That's nonsense! Why would I steal my own ring?"
"You were alone in the bedroom," Keiko shot back. "You could've hidden it to frame us!"
"You three are all broke. Even if I framed you, could I extort anything?" Rina snapped.
"Who're you calling poor, you bitch?" Keiko yelled.
As the women began arguing again, Officers Matsumoto and Morimura rushed to separate them.
"Inspector Samezaki, I have a method that might identify the thief," Shuichi said.
"Might? Be clear," Matsumoto grumbled.
"It's worth a try," Samezaki said, eyeing the four women. "You'll all cooperate, right?"
Refusal would raise suspicion, so all four nodded.
"Extend your hands," Shuichi said, picking up the iodine from the table. "Eri, apply it to their fingers."
"Iodine…" Eri paused, then her face lit up with realization. "Shuichi, I get it."
"Let's apply it first," Shuichi said. "I'm not sure if it'll work."
"What are you two on about?" Kogoro asked, confused. "Just say it!"
"Patience," Shuichi smiled, holding off on an explanation.
Eri dipped a tissue in iodine and applied it to each woman's fingers.
"What's this for?" Rina frowned. "My fingers aren't injured."
"Wait, why's the iodine on your fingers turning blue?" Saki Imagawa asked, surprised.
"Iodine turns blue when it contacts starch," Keiko said hesitantly. "It's been years since I graduated; I barely remember this stuff."
"Exactly. Reddish-brown iodine turns blue with starch. Middle school chemistry," Shuichi confirmed, turning to the quiet Mika Hirata. "Ms. Hirata, don't curl your fingers. Open your hands so we can see."
"I…" Mika grew visibly nervous, clenching her fists.
Her reaction was suspicious.
"Ms. Hirata, please cooperate," Samezaki said sternly.
"Mei Xiang, don't be scared. You couldn't have taken the ring," Rina said, stepping forward to pry open Mika's fist. Her right index finger and thumb, coated with iodine, had turned blue.
"The paste's main ingredient is starch," Shuichi said slowly. "Ms. Hase said she alone made the paste and applied the talisman."
"The talisman paper is old and wrinkled, so when Ms. Hase applied it, her fingers got paste on them, turning blue with iodine."
"But you, Ms. Hirata, when did you touch starch?"
"You're saying Mika stole my ring?" Rina said, stunned. "But that's impossible. Mika doesn't need money."
"Is this a mistake?" Saki added. "Mika's so honest and well-behaved. She wouldn't do this."
"Meika, say something!" Keiko urged. "You didn't take it, right?"
The three women, moments ago at each other's throats, now defended Mika.
Under their gazes, Mika said softly, "No, he's right. I stole the ring."