Bengtie: My death fueled their madness.

And so, Mu and Heita lived a life of mutual dependence.

They spend their days immersed in their own worlds, only having time for each other when night falls.

However, in their limited private time, they still choose to immerse themselves in the ocean of knowledge without prior agreement.

Only on very rare holidays do I temporarily allow myself to do other things.

Play ball, take a walk hand in hand.

When they got tired, they sat on a public bench by the roadside, snuggling together and quietly enjoying the rare moment of peace and quiet.

"Brother Mu, if humanity truly gained control over time, was it possible to change the past or the future?"

Hei Ta held the warm milk tea and leaned on Mu's shoulder.

"I don't know. Since you're asking me, you must have your own answer, right?"

Mu shook his head, noticing the faint sadness emanating from the girl, and put his arm around her shoulder.

He knew better than anyone that the girl could never get over her parents' sacrifices.

His tireless research into space and time is far more than simply fulfilling his parents' wishes.

"Actually, I don't know either. The present, the past, and the future are paradoxical in themselves, and are closely intertwined with cause and effect."

Black Tower lowered his gaze, his voice low.

Mu understood what he meant, agreed, and gave examples.

"For example, if you go back in time and save your uncle and aunt, then your future in that timeline will be changed as a result, and that might also affect me."

"You might not be able to study so diligently that you'll eventually find that the timeline you've altered overlaps with the present. This means that because you changed the past, you won't have the same ability in the future and won't be able to control time."

"By then, if past changes contradict future changes, how will the cause-and-effect relationship complete its closed loop?"

"My analogy may not be very vivid, but you should be able to understand the general meaning."

"…certainly."

Black Tower sighed softly.

"This is where I'm most confused, Brother Mu. Let me do a little experiment for you."

She untied the hair ribbon tied around Mu Zai's temples, brought it to her face, and loosened her fingers under his gaze.

The hairband fluttered lightly onto her legs.

"If I loosen the headband, it will fall down, but—"

She picked up the hairband again and continued:

"If I knew, or was aware, that the headband would fall off in the future..."

Hei Ta loosened two fingers on her left hand, but caught the falling hair ribbon with her right hand, and looked up at Xiang Mu.

"Look, the future has changed. This may mean that there is more than one future. As long as we can realize it in advance, we have the opportunity to change it."

"What we lack now is to lift the headband back up and restore its ability to function as it was before we realized it would fall off."

"By returning to the same points in the past and intervening and making appropriate corrections, we can ensure that the altered past does not lead to even more terrible changes in the future."

Mu opened his mouth, unsure how to respond.

This isn't his area of ​​expertise; he can understand it, but he can't offer any deeper insights by citing classical texts.

Perhaps the Black Tower's idea wasn't wrong, but...

Even if you can control time and space and go back to the past to change many things, what about cause and effect?

The hairband is an inanimate object, devoid of complex emotions and entanglements; its future is clear, and it is at the mercy of others.

But people are different.

Everyone is caught in a chain of cause and effect, where a small change can have far-reaching consequences.

Do humans truly have the ability to control and modify cause and effect?

Mu Xinxin held a pessimistic attitude.

Fortunately, Black Tower did not delve further into this heavy topic.

She retied her hairband, drawing in the reassuring aura of the boy beside her to dispel the fatigue accumulated from days of dedicated study.

Night was falling.

"Go home."

The evening breeze was quite strong and it was quite cool.

Mu carried the black tower on his back, shielding her from the oncoming wind, and let her put her little hands inside his collar to keep warm.

Not long after I walked, I passed a familiar milk tea shop.

"Brother Mu~~"

"it is good."

Hearing the woman's soft, coquettish voice, Mu's lips curled up slightly, and he stopped in his tracks.

Black Tower, familiar with the place, ordered two drinks.

She always says that consuming sugar in moderation can effectively relieve fatigue caused by excessive mental exertion.

However, Mu, who was studying medicine, knew that this statement was actually not rigorous and had no reliable basis.

It's true that using your brain a lot significantly increases glucose consumption.

The lost sugar cannot be replenished by consuming regular sugar.

However, Mu naturally wouldn't point out such a trivial matter.

He kept this in mind and developed a nutrient to make various kinds of candies in different flavors.

The lollipops were the most numerous, and the entire contents were packed into a large transparent jar, which I put into my black tower crossbody bag so I could take them out and eat them anytime.

Eating too much won't harm your body; at most, you just won't be able to absorb it all.

One day, after taking a shower, Heita found Mu watching a movie.

"What is Brother Mu looking at?"

"Disorder, a zombie movie, wanna watch it together?"

"Um."

The girl sat down close to the boy, her head naturally resting on his shoulder, and habitually opened her mouth to bite the piece of fruit he offered.

Disorder is rated as restricted and contains many gory scenes.

Ke Mu and Hei Ta watched the scenes of zombies devouring people and tearing human bodies apart without much expression.

About half an hour later, a message suddenly came from the Black Tower's joint government terminal.

A breakthrough was achieved in a key problem, and she needed to follow up immediately, so she stopped looking at it.

By the time I finished all my work, it was already time to go to sleep.

After hearing Mu's negative review of the movie while I was in bed, I lost interest in finding out what happened next.

A few days later, Mu took her to watch a movie of a different genre, called Deadly Mirror.

This time, I also didn't finish watching the Black Tower.

Since no important figures in the coalition government have been involved in any incidents, Mu generally doesn't need to take charge of major surgeries, so she is much busier than Mu.

When she finished her work, all she got was a bad review from Mu, and she had no interest in watching it again.

The two gradually developed similar personalities: they would never waste a second on things they weren't interested in, and not giving up halfway through was considered a sign of patience.

This peaceful and warm time did not last long.

That night was Black Tower's 10th birthday, three months after Mu's 12th birthday.

The girl was gradually taking on the appearance of a young woman, although she hadn't grown much taller and her development was rather slow.

Yet, on that youthful and beautiful face, there was a composure and maturity beyond her years.

Mu is different; she grows very quickly, almost abnormally so, reaching a height of over 170 centimeters.

Wearing a white coat and a mask, it would be hard for outsiders to associate him with a 12-year-old boy.

No matter how tall he gets or how upright his figure is, he will always be the Mu-gege who would carry the Black Tower on his back, hold her hand, and go home together.

After her parents passed away, she spent the happiest birthday night of her life with Mu by her side.

And all the beauty was frozen in time on this night.

The following day, an emergency distress call came from the border fortress in the maze area, with unprecedented casualties.

As one of the highest-ranking doctors in the United Government, it was his duty to rush to the front lines.

Before he left, he only said, "Wait for me to come back."

She said to be careful.

In the end, the girl did not wait for Mu to return, but only received a cold message.

The border fortress completely fell and was incorporated into the labyrinthine area covered by the Memory Mist, forcing the human defense line to retreat hundreds of kilometers.

The mist emanating from the void of memory grew thicker and thicker, constantly merging reality and illusion, giving birth to more subspaces and illusory life forms.

She once lost her closest relatives.

Now, even the last person who stayed by my side has been lost.