Ch.2121. Memento Mori.

“My view is this. The time where she… where Mori exists is ‘a future where we have already received Mori’s video and acted upon it.’ Even if it wasn’t the case until now, it’s correct to say it became so the moment this world received the video.”

“Why do you think that?”

“Because if some action had significantly altered the ‘unknown time’ between us and Mori and greatly changed the future, that video wouldn’t still be visible to us.”

“…So you’re saying all probabilities and variables in the world have become fixed? Even our words and thoughts?”

“At least regarding physically existing variables… yes, I believe so.”

“Nonsense! Perhaps you should surrender your degree and take up writing novels instead?”

The scientists considered Eugene’s words far more absurd than Mori’s video.

Scientists who analyze the microscopic world—where even light particles cause changes and show countless variations with each observation—were reluctant to accept Eugene’s claim that a series of future events and all upcoming variables were essentially fixed.

“No, wait. Thinking about it, we can’t say his words are completely wrong.”

However, Eugene’s theory wasn’t entirely far-fetched.

Everything being done to escape the apocalypse after watching Mori’s video is, from the perspective of 21st century humanity, something that will happen in the future—an uncertain future.

But in Mori’s world, so distant in the future it’s hard to comprehend, these events are merely past occurrences in the flow of time.

Analyzing causes and controlling variables through events that have already occurred is the privilege of someone who exists in the same timeframe as the phenomenon or in its future—not the privilege of a “cause” existing in the past.

“…Perhaps what this means is that our intended words and actions became the cause of that world.”

“That’s exactly what I’m trying to say! Taking countermeasures is right. It’s necessary and the only way to escape humanity’s extinction. However… I believe our current approach—short-term, material solutions that directly affect Mori—is wrong.”

“…Fair enough. Debating scientific proofs of our current era when faced with footage from the future probably isn’t very meaningful. Everyone seems to have a lot to say, but for now, let’s assume what this young man says is true and proceed from there.”

Who would have ever thought someone from the future would directly intervene in the past through video? Setting aside the thought, no one even believed it was possible.

Scientists, mathematicians, and those who explore supernatural phenomena must primarily pursue “unchanging truths.”

But at this point, when the truths they believed unchangeable have shifted, they needed a completely different perspective.

“According to you, this world will eventually end, no matter what actions we take, since we’ll reach the future where she exists.”

“At least at this point, yes. With such clear evidence that time flows in a single line, there’s no need to debate it.”

“Then let me ask you, Eugene, do you have any strategy to resolve this situation? As we all know, changing an undetermined future is easy. We just don’t realize it.”

If a pendulum’s angle shifts by just 0.00001 radians, the pendulum moves in a completely different pattern.

Similarly, changing an unobserved outcome by introducing minor variables isn’t difficult. We simply can’t observe what caused a particular result until we compare each variable one by one.

“But nowhere is there any information on how to change a predetermined future, and no one has ever considered this problem. There was no need to think about it. Who could have predicted that we, who thought we were always the ones attaching beads to pendulum strings, were actually the beads hanging from the string?”

A bead hanging from a string cannot know how many degrees it has tilted.

Nor can the bead know whether its movement has a meaningful impact on the outcome.

“That’s why I believe proper communication with her is essential. She needs to recognize that humanity’s survival rests in her hands, and she must find the cause of the extinction that has already occurred and ways to counter it, so we can attempt what is ‘impossible by this era’s common sense.'”

An elderly man who had been listening attentively to Eugene spoke. He was among the most active in trying to establish direct communication with Mori, sending messages to the site where the videos were uploaded.

“But you don’t seem to think so?”

“…That’s correct.”

Eugene, unlike the old man—no, unlike numerous scholars who insisted on discussing the extinction of humanity with Mori—had a different opinion.

“It’s far too early to talk about the 21st century. She isn’t ready to accept that she’s talking to people from the past rather than living people, and we still know nothing about what happened in the future.”

“That’s precisely why we should help her learn the truth as quickly as possible, so we can work together on countermeasures, don’t you think?”

“No. No. Conversation with her could be the solution to the apocalypse, but conversely, it could also be the trigger that hastens it. You’re all mistaken about something—the person in the video isn’t a scientist like us or a hero from a fairy tale. She’s just an ordinary person!”

In the ruined city, all that can be seen are corpses, and all that can be heard is her own voice.

In such a bleak environment, Mori has endured alone for a whole year.

Even someone with the strongest mental fortitude would waver in such circumstances. What has allowed Mori to persevere is just one thing:

The faint hope that survivors exist somewhere in the world.

“Let’s say we send her a message explaining that everyone watching her video is humanity from the past, that humanity is certainly extinct, and asking her to find the cause so we can survive. Do you really think she would remain stable after seeing such a message and accepting that reality?”

As long as there is hope to cling to, people don’t easily break down.

Conversely, the moment the only hope they’ve been clinging to collapses, a person’s mind breaks down. We call this falling into despair.

“People aren’t rational. Decisions always involve subjectivity, and people don’t hesitate to fall into confirmation bias to maintain their sense of self. But that very irrationality is what has sustained her until now.”

The world has long been extinct.

No trace of life can be found anywhere.

The weather is like an ice age with endless snow, leaving no possibility for new life to bloom.

If Mori were a purely ‘rational’ person, it wouldn’t have been strange if she had taken her own life like the many corpses she’s placed in her drone.

But Mori hasn’t stopped living despite the long period of despair, and hope has been the foundation of her journey.

Her determination was so strong it could be felt even through videos that traversed hundreds of years.

The problem was that the spark of hope she had maintained for a long year was gradually fading.

Just as she often said that life and death, hope and despair coexist.

She has long accepted the despair that might soon befall her, even as she smiles with hope.

“If she takes her own life after learning the truth… we will forever lose the means to escape the apocalypse. Not only that, but the only human who could change the world would disappear, leaving only the ruined world behind, making it impossible to avoid extinction.”

The human world exists only because human will exists.

Without the will to observe the world, without humanity, neither time nor space, neither matter nor phenomena, neither hope nor despair can be observed.

Eventually, all worlds and definitions would disappear.

Of course, traces of humanity’s existence would remain—collapsed buildings and scattered corpses.

But can a world that no one remembers or observes truly be said to exist?

Therefore, Mori is humanity’s last will, the world itself.

Mori’s death would mean the complete end of the world.

“If Mori dies, or even if she doesn’t… the moment the future changes even slightly, the video will cut off. But can we be certain that our future has changed just because the video cuts off that way? Rather, Mori’s death could spread the desperate ideology underlying the city, bringing about an even more terrible apocalypse even sooner.”

Moreover, even if contact with Mori alters the future and cuts off the video, that alone isn’t direct evidence of escaping the apocalypse.

Just as a half-eaten apple and a quarter-eaten apple cannot exist in the same place.

The extinction of humanity might remain predetermined, with only the process or timeline changing.

What if the video cuts off because of Mori’s death?

In just a few weeks, doomsayers and religious zealots have filled the streets. This would be like pouring oil on their fire.

The world would descend into chaos more quickly, and the apocalypse would certainly be hastened, Eugene thought.

“That’s why I believe direct communication with Mori should be avoided until the very last moment. The only thing that can save humanity now is her will.”

“Then what is this ‘last moment’? Won’t she give up on life the moment she learns the truth, regardless of when it happens?”

“We must guide her to help humanity now, even without her intention. To reach across hundreds of years into the future. And all while ensuring she doesn’t realize this path was laid by past humanity seeking salvation through Mori.”

From this moment until the time Mori exists has become connected, unchangeable no matter what is done.

This also meant that from now, over hundreds of years, they could lay a path for Mori to save humanity through her future—a future not yet observed.

“It would have been impossible if the time between Mori and us was short. The shorter the time, the greater the direct impact a single variable would have on the time she exists. But as we can see from the intact video, our plan apparently doesn’t significantly affect humanity’s primary extinction.”

“So you’re saying our plan successfully reached her time. Another interpretation could be that even our efforts are meaningless… but this is the most hopeful idea we’ve heard so far.”

“Good. We need to start a project spanning hundreds of years. An absurd project where humanity living in the ‘past’ asks the ‘future’s’ last human to save the ‘present.'”

No one knows if this is truly a viable project.

But just as Mori has endured in an empty city until now.

Those who have discovered hope for the first time decided to cling to it.

“Wait a minute, but is there any project that could continue for hundreds of years? Even after urban civilization ceases to function?”

“Material things don’t mean much at this point when we don’t even know Mori’s location. Right now, we need ‘will’ and ‘truth’ that can universally affect future human history and technology.”

“That’s too philosophical and… vague an answer for me to understand. Could you give us some examples?”

Someone asked Eugene, who had somehow become the center of the project.

[When I get to the next city, I should first… look for a library.]

Looking at Mori in the video saying she needed to find a library, Eugene slowly began to speak.

“For instance, how about something like: ‘All human history and knowledge shall be preserved in books and paper in the safest places, to outlast humanity itself’?”

Each of these thoughts and words already exists as past events and results in Mori’s world.

“Good. Starting with such intentions, let’s find what we can do and must pass on to the future. I’ll leave this to you, Eugene. And we’ll simultaneously proceed with material projects, like constructing landmark buildings.”

“Excellent. Let’s all set aside achievements and rewards for now, and work together until we save humanity.”

“By the way, a massive project spanning hundreds of years needs a catchy name. Have you thought of one?”

“…I haven’t thought of one specifically, but if I were to name this long journey to save humanity from extinction, one phrase comes to mind.”

“Haha, whether by coincidence or fate, I think I know what you’re thinking.”

In honor of the girl wandering alone through an extinct world.

Even if the people here now die as time passes.

Hoping desperately that future generations never forget the approaching apocalypse.

People wrote down two words.

“Remember death.”

—Memento Mori.