Chapter 73

The fox-eyed one hesitated for a moment at the truth I presented, then pressed me for a single answer.

"Hold on. Why did Uchima make the mistake? Why did he mix up the pesticide-laced sugar and the food-poisoning bacteria-laced sugar? It's a matter of life and death. Who would make such a mistake?"

"There's a reason for the mistake."

"What kind of reason?"

To give that answer, I'll explain what Uchima was plotting at the time of the incident.

"Uchima left a note hinting at suicide, and asked a detective to watch him. I think he stopped by the café on the second floor to show someone who was watching him receive the sugar. So, what do you think would happen if a food-poisoning incident occurred on the fifth floor using that sugar?"

"How does that explain the mistake... I don't get it... the people on the fifth floor café would shift the blame to the second-floor café. Then, something else would come to light... right. The second-floor café would face even greater malice. As retaliation for being suspected... this was part of Uchima's revenge too."

"Exactly. To make life unbearable within this department store. Now, I'll give you the answer. Amid such a plan, Uchima, who put the sugar into his pouch—he—"

"He...?"

Hearing the fox-eyed one echo it in a strong voice, I recalled.

The hint was when something spilled from my pencil case. That's how I realized this tragic truth.

Accepting the sad truth, I spoke my deduction aloud.

"Someone—while he was in the restroom—emptied everything in his pouch onto the floor and ransacked it. While putting it back in the pouch... the positions must've changed! The positions of the sugar packets!"

"The positions changed? Why separate the pesticide-laced sugar from the food-poisoning bacteria-laced sugar by position? You could just mark them."

"If the marked sugar was left sitting out, someone would notice, right? And it'd be unnatural to take home the used sugar trash. He wanted to avoid the plan failing from someone reporting it before the food-poisoning scare..."

"O-oh, I see..."

"He must've kept the bacteria-laced sugar separate by slipping it into a memo pad or something..."

"Enough with the explanation. Who was it!? Who's the real culprit!?"

...I don't know. Is it even right to call them the real culprit? No—there's no mistake they're the one who triggered this string of murders.

Let me speak.

"This incident was probably not deliberate. It was a murder even the culprit could never have predicted...! Hasegawa Emi. She is the culprit behind this case!"

A person no longer in this world. If this deduction is wrong, it will tarnish her honor.

So, one step at a time, carefully. Yet to show the fox-eyed one I'm serious, I delivered each point in a heavy tone.

The fox-eyed one responded to my words.

"She... the victim was the culprit...? Then Haruki carried out Uchima's revenge!?"

I instantly denied that misunderstanding.

"No. The person who killed Ms. Hasegawa... was also Ms. Hasegawa herself."

"Huh!?"

"It was suicide. Ms. Hasegawa used Haruki to commit suicide!"

"Wait... what!? Ms. Hasegawa committed suicide...!? How does that work!? I get that the guilt of accidentally driving Uchima to death could lead to suicide, but why drag Haruki into it!?"

This is the tricky part of the case. Ms. Hasegawa's suicide probably stemmed from regret over having killed someone, even by mistake. But that's not all.

I put my thoughts into words.

"I'm sure Ms. Hasegawa... inherited it."

"What?"

"Uchima's revenge... she carried out this incident to punish Haruki, the one he hated most."

"So... she tried to saddle Haruki with the heavy crime of murder...?"

"Exactly."

"That's impossible!!"

Hearing her shout, I reflexively tensed. Then I asked what information she was using to refute my conclusion.

"What do you mean?"

"If Haruki isn't the murderer, she could just act openly. She wouldn't need to fear reporting it. No need to be jumpy around the police. Why run from the crime scene in the first place!? If she's not the culprit, what reason could she have for not coming forward as the first witness?"

"...Did you forget what I said at the very start?"

"What!?"

Her face contorted violently as she reacted. I slammed the deduction home.

"I said it. That Haruki made this case more complicated... right. I think Haruki didn't commit the murder, but she did abandon the corpse."

"Abandon the corpse!? Wasn't she strangled in that park!?"

"Yes. Probably in the park. And in a spot normally no one would notice—Ms. Hasegawa strangled herself."

"Huh!? Inconspicuous... are you saying she attempted suicide in the restroom!?"

I pulled out my smartphone and showed the fox-eyed one the photos I'd taken in the park restroom.

Inside the restroom, only odd spots had been wiped clean—the lid, the doorknob. I conveyed what the traces revealed.

"Yes. Everything had been wiped to erase the traces... A rather troublesome trick. Ms. Hasegawa entered the near stall, looped a rope around her neck, then threw the other end of the rope over into the far stall. She threaded it through the gap under the far door or over the top..."

"Then?"

The partition between the near and far stalls. The dust had been rubbed off the top, likely from this setup.

"She wound the rope around the doorknob on the far stall's entrance side. The knob was wiped clean, probably so Haruki could hide the fibers left by the rope."

"Huh? Why would Haruki do that?"

"Ah, right. That ties into how Ms. Hasegawa framed Haruki. She probably waited until Haruki's shift ended and she was about to leave, then knocked her out from behind with anesthetic or something and dragged her into the far stall—the one with the trap already set."

"O-oi, you mean—!?"

The fox-eyed one seemed to realize. The horror of Ms. Hasegawa's homemade automatic killing machine—and how it must have shocked Haruki.