Satoko-chan's dissection plan has been scrubbed, and we are getting ready to administer an almost totally untested medicine, C103.

This experimental medicine suppresses the production of a certain type of hormone and, in doing so, it will stop the transmission of the syndrome triggering Satoko-chan's condition.

The mechanism of Hinamizawa Syndrome is as follows: the pathogen takes over the frontal lobe of the patient's brain, and then induces increased responsiveness to paranoia.

As a result, a patient voluntarily carries out excessively defensive behaviors, to a problematic extent.

If this induction can be cut off, then it'll be possible to save terminal patients from becoming deranged.

But it only cuts off an induction, so it's not really a cure.

...Ironically, the brain is an organ that learns.

Once the brain has learned to be excessively paranoid due to the Hinamizawa Syndrome, even after the pathogen is eliminated, the brain doesn't simply unlearn that paranoia.

In short, even if the pathogen doesn't induce derangement, the patient will be directed to such emotions of their own volition.

...Thus, it is impossible to completely escape the nearly-deranged L5 state.

(The proverb, "a burnt child dreads the fire," is a good example of this.

Even after the burn on your tongue heals, the fear of being burned by food again remains.

When it ends up being a good thing, we call it "learning a lesson\

We predict Satoko-chan's treatment will take a significantly long time; requiring both medication, such as administering psychotropics, and mental care, like counseling.

We have to slowly unravel her mind's solidified paranoia while also suppressing the syndrome's induction of derangement.

...This is the treatment plan for terminal patients like Satoko-chan.

However, as we are going to stimulate the parts of her brain that affect her emotions while they are being stimulated by the pathogen at the same time,

it's possible there could be unexpected side effects.

Both her mental and physical strength hold the key to our success.

We were going to begin the experiment once she regains her emotional stability and physical strength, but...

Someone who threatens to disturb her emotional stability has been coming here every day.

...Ooishi, the sly old detective from the Okinomiya police department.

He thinks everything, from the dam protests to the dismemberment murder of the construction manager, is an organized effort secretly conducted by the Three Families of the village.

He even thinks the accident involving Satoko-chan's parents wasn't an accident. That's why he keeps coming back so he can talk to Satoko-chan.

"No matter how many times you come, I won't let you see her.

She's still crippled by the shock of her parents' deaths.

Can't you understand what she's been going through?"

"I understand. I only need a few minutes with her, really.

It won't take long at all.

If you want me to get a warrant, I will. But that's pretty serious, you know?

I'm being considerate of Houjou-san, and that's why I haven't gotten a warrant."

"What are you trying to ask her anyway? I don't really understand."

"...Hmm, well, actually...

It's possible that the fall was not an accident."

"I know the Houjou couple were hated by the whole village after the business with the dam.

But who would actually follow them on their trip and push them off? Don't you think that's absurd?"

"Hmmmmm.

Well, we could call it an accident.

But if that was the case, there are some things which just don't make sense.

Why lie?

With those lies, I don't think it was an accident."

"What lies?"

"Well,

Satoko Houjou-san said she was asleep in the car at the time of the accident.

...I think that story sounds a little off, doesn't it?"

Satoko-chan claims she was asleep in the back seat when the accident took place.

So she didn't get out of the car at the viewing platform.

When she woke up, she didn't see her parents.

Then she found out they had fallen off the cliff.

"Where is the lie, exactly?

You aren't saying Satoko-chan wasn't really asleep and she went over to the viewing platform with her parents, are you?"

"That's right.

Satoko Houjou-san was never asleep.

She got out of the car with her parents and went to the viewing platform."

......I'm suddenly hit by a terrible possibility.

If what Ooishi says is true, and Satoko-chan is saying she didn't go to the viewing platform even though she actually did...

It's terrible to even imagine.

"Why are you saying such a thing?

Besides, why would Satoko-chan lie?"

"That's just it.

Why would Satoko Houjou-san lie?

That's why I need to talk to her.

...Otherwise, this won't end as just a simple accident."

"Why are you convinced that Satoko-chan is lying?"

"This accident took place in a different jurisdiction. The guys from the Shirakawa station conducted the interviews with the parties involved.

There are things that bother me in their report."

"Bother you... Like what?"

"According to Satoko Houjou-san's statement,

her parents asked her to come with them to the viewing platform, but she was sleepy, so she didn't get out of the car.

Then she fell asleep and woke up after a while.

She became concerned because her parents hadn't come back, and started to cry.

One of the park workers on patrol noticed her crying and talked to her, and that's how the accident was discovered.

And at that time, guess what?

According to the park worker's testimony, she was the one who first said her parents had fallen off the cliff.

But, you see, it's hard to see the accident site in question from where the car was parked.

If you look very carefully, you might be able to notice the broken fence.

But still, you know...

I think it's odd to say your parents had fallen off a cliff just because you didn't see them when you woke up.

Normally, most people would say something like their parents went for a walk and didn't come back.

It just doesn't make sense to me that she told a stranger that her parents had fallen off a cliff without even being at the site of the accident!

I want to ask her why she was so certain that her parents had fallen off a cliff. That's why I keep coming back here.

I asked her many times before she was admitted here, but all she said was that she doesn't remember or that she was confused at the time. Sounds like a politician, huh?

That's why I think it's worth taking that time to talk to her."

That terrifying possibility has turned to certainty in my head.

I'd assumed that her parents' accident triggered her terminal symptoms.

...But no.

Satoko-chan had already gone terminal, and just before the accident, her heart was filled with paranoia that drove her mad.

She was under a lot of stress because of her bad relationship with her stepfather.

She was also being scolded by her mother for not being able to get along with him.

...If that made her paranoid, made her think her parents considered her to be a bother and were going to kill her...

When they went to the viewing platform, she must have thought they were going to push her off the cliff.

Then a tragedy took place, and she pushed her parents off instead, although she considered it to have been self-defense.

I'm certain of that

because I know Hinamizawa Syndrome better than anybody.

This accident isn't an accident.

...It isn't a crime either, like Ooishi is thinking.

It is simply

a tragedy.

When I talked to Satoshi-kun about the family, I was even more convinced.

He told me even though Satoko-chan refused to open up to her stepfather, he had tried to communicate with her.

It's true their relationship didn't go well in the beginning.

Satoko-chan caused trouble repeatedly, and even called the city's child abuse hotline.

At that point, they received guidance from the child consultation center, and they pointed out that the problem lay in lack of communication between daughter and stepfather.

So the stepfather took a parenting course under the social worker's guidance, and awkward though it was, he made efforts to communicate with her.

Satoshi-kun noticed his efforts, so he tried to talk to Satoko-chan about it.

But Satoko-chan didn't notice them at all.

The excessive stress she was under triggered terminal symptoms...... and she couldn't understand her stepfather's remorse.

...On the contrary, her stepfather's change created even more mistrust within her.

As a result...

they went to enjoy the beautiful view of the Shirakawa Nature Park as a family

and to share in that joy...

Yet that humble, ordinary family's wish...

couldn't even get through to Satoko-chan.

...What a tragic misunderstanding...

Satoko-chan stayed in the car telling her parents that she wanted to sleep, but then she got out and snuck up behind them.

I bet he heard her footsteps.

He pretended not to notice her,

thinking that she was doing that to surprise him.

...It's sad just thinking about what must have ran through his mind.

While he thought he had finally gotten through to her,

she was actually approaching him with the intent to kill.

But that's not Satoko-chan's true nature.

It's the disease.

Satoko-chan isn't the only one who is to be pitied. Her parents are its victims, too.

And now, Ooishi thinks she's a criminal.

Judgment and punishment are required for crimes with malicious intent.

But what she really needs is understanding and sympathy.

And no one has that understanding. Except for me, because I know about Hinamizawa Syndrome.

I am the director of the Irie Institute, but I've never behaved as such or exercised that authority.

But I'm going to do so for the first time since taking the position.

I'm not doing it as the head of the Irie Institute, the secret research organization.

I'm doing it as a doctor, so I can protect Satoko-chan.

"It's about the Houjou family's accident at the Shirakawa Nature Park...

Do you think you can ask Okonogi-san from the Mountain Dogs to make it out to be an accident?"

"Sure, of course. That's no problem.

The Mountain Dogs are a unit specialized in concealment and manipulation, after all.

We have to put an end to it quickly, otherwise the police will end up getting closer to finding out about our research."

"...That's right.

Please make especially sure Ooishi-san is drawn away from this case.

We're at a delicate stage of the drug administration test.

She doesn't need any more unnecessary stress."

"You're absolutely right.

I'll let the Mountain Dogs know.

I've heard they even have connections within the police, so I'll give the order to put pressure on them, too.

I'm sure the accident in Shirakawa will be concluded as exactly that within a few days."

With that, it was declared an accident.

If only it really was one, it would have eased Satoko-chan's soul...

Getting rid of the pathogen can't heal that wounded soul.

Nor can it erase the tragedy that had already taken place.

All I can do is my best,

so the day she regains her smile comes sooner.