Part 5

Se Yue: ...Feels like you've changed a bit from the you of two days ago.

Wu Shi: Yeah, I've made certain realizations about myself.

Se Yue: Mmm, that's good.

Se Yue smiles.

Se Yue: As a reward, I will share my biscuit straws with you!

Wu Shi: Uhhhh... nah, I'm good, thanks.

Se Yue: Eh? Come on, you don't need to resist it, I'm really willing to share these with you.

Wu Shi: Why are you acting like you're bestowing some great honor on me?

Se Yue: Because these biscuit straws are highly precious!

Se Yue: Usually my family doesn't let me have these. They tell me that snacks aren't good for your health.

Se Yue: If it weren't for the fact that there's nobody to watch my every action on the Tour of Time, I couldn't even have smuggled these on in the first place!

Wu Shi: ...You've worked really hard for these, huh.

Se Yue: Let me tell you, you all are too used to having cheap snacks readily available. You've got no respect for their luxuriousness.

The more I got to know this haughty young lady, the more I saw there was another side to her.

I supposed everyone had an imperfect side to them.

Se Yue: So, last time, we were explaining how absolute time is defined by the time perception of humanity, and if there's only a single person riding the train then that person's time perception represents all of humanity, meaning that one person's experience of time is equivalent to Absolute Time.

Wu Shi: Last loop you also explained that you had no way to change Absolute Time.

Se Yue: So, we won't change it. Under this prerequisite, we can still pull time to the past.

Wu Shi: What is this? A tire?

Se Yue: Isn't it self-evident? It's a clock.

What a hypermodernist depiction of a clock.

Se Yue: Now, this is the clock we use normally.

Se Yue: Modern humans use a base-twelve system, as the representative units of time.

Se Yue: Which is to say, the Absolute Time right now is 3AM.

Se Yue drew in an hour and minute hand. The long minute hand pointed towards 12, while the short hour hand pointed towards 3.

Se Yue: Now, let's make some changes to this clock.

She drew in some modifications.

Se Yue: Can you tell what's been added?

Wu Shi: A thirteenth hour...

Se Yue: In this new clock, the angle represented by the 3rd hour is smaller than previously, right?

Se Yue: Thus, time has moved backwards, right?

Wu Shi: ...So that's how it is...

Se Yue: From this image we can see that, if we are capable of inserting the nonexistent thirteenth hour, then Absolute Time will be forced to move backwards relative to its previous position.

Se Yue: The forward progression of the Tour of Time is the forward progression of the time axis.

Se Yue: The twelve cars of the Tour of Time represent the twelve numbers on the clock.

Se Yue: Therefore, adding a thirteenth train car is equivalent to adding in a thirteenth hour.

Se Yue: This is also why we need to use the dead as fuel, and furthermore it must be someone who died less than 12 hours ago.

Se Yue: Only those who have passed beyond the living world possess the unique property, of having a perception of time which does not exist in this world.

Se Yue: From the perspective of mysticism, this is because death desynchronizes the physical corpse and the soul, but doesn't completely detach them

Se Yue: The 13th boxcar that carries the dead person thus becomes the 13th hour that does not exist in this world.

Se Yue: That's how the Tour of Time is able to achieve the reversal of time while keeping the user's Absolute Time constant.

Wu Shi: Wow..... that's incredible.

Se Yue: Well, it's not that incredible. There's some flaws to the design.

Wu Shi: Okay, so, how many people have suffered Lost Time Syndrome now, then?

Se Yue: 48 people.

Wu Shi: So that makes S a killer for fun?

Se Yue: No, remember, every loop requires the use of a new source of fuel.

Wu Shi: Oh, riiiiight. Sorry, this is all a lot to take in.

Se Yue: Furthermore, even if S didn't need to kill anyone, fuel would automatically self-generate anyways.

Wu Shi: What's that mean?

Se Yue: The user is constantly accumulating time; in the second loop, their hearts contain the equivalent of two 3AM's worth of Absolute Time, which means that more Fuel is needed to counterbalance.

Se Yue: 48 loops of time requires 48 units of fuel.

Se Yue: To fulfill this requirement on a causal level, the universe will use all sorts of bizarre methods to automatically take lives away from people.

Se Yue: In the loops prior to this one, some small fraction of these people may indeed have been directly killed by S, but the absolute majority probably died of inconceivable accidents or coincidences.

Se Yue: In the last loop, besides me, there was likely some other victim, and S chose to place this other person in the train car. That's why I didn't fall over from Lost Time Syndrome at the start of the loop.

Wu Shi: Could it have been because they were a member of Cesium as well, and thus had some degree of respect for you?

Se Yue: No, I'm pretty sure that respect and being beaten into hamburger are incompatible, you absolute fucking moron.

Se Yue: In any case- in the most extreme case, as the number of victims increases, S will show his identity sooner or later, through the method of elimination.

Se Yue: There's only a hundred students and a hundred maids here; by that logic, once we reach the 200th loop, the only survivor will be S by default.

Se Yue: Yeah, that sounds about right. It's a reasonable theory.

Se Yue: ... But I still think that the fact that you've got your memories intact could be due to a deeper cause.

Se Yue: If only Qian Yuan were still around. She's the only person I know who's actually directly used the time-machine, she has hands-on experience that I don't. I only know all of this as theory.

Wu Shi: Perhaps S killed her specifically to prevent her from telling us anything useful she might have known...

Wu Shi: So, how do we end the loops?

Se Yue: We just need to make S give up on looping.

Wu Shi: So, we can't get around finding out who S is, huh. We have to figure out the identity of S so we can make them stop looping...

Se Yue: That, or we can disassemble the three necessary components for the time loop.

The three required elements of the time loop are...

Water, air, and sunlight.

S, Lost Time Syndrome, and a sealed underwater environment.

The operator, fuel, and the Se family crest.

Se Yue: Yep. So, that means there's three actionable ways to stop the loop.

1: Don't let the user board the train.

2: Don't let the fuel get loaded into the thirteenth train car.

3: Don't let the crest get stolen.

Se Yue: The first one isn't exactly viable anymore; the second one is difficult for you, because you die at noon today, and that means you have no power to affect the 12 hours after your death.

Wu Shi: So why don't you do it, in my stead?

Se Yue: I can't.

Se Yue: What do you think will happen, if it becomes obvious to S that I've become your agent?

Se Yue: S will take steps to stop me, permanently.

Wu Shi: Okay, then we're just left with the third option- prevent him from getting the crest.

Se Yue: I feel like that's also useless.

Wu Shi: Why?

Se Yue: According to you, I haven't been able to keep the crest from him a single time.

Wu Shi: So just give me the crest and let me hide it.

Though my suggestion seemed reasonable, she didn't hand it over, and instead took on a peeved expression.

I knew what she was thinking, immediately.

Was this person S?

From her perspective, this was the first time we'd had a real conversation, and she had no real guarantee that this wasn't exactly how I talked her out of her crest on every loop.

Maybe I'd 'changed' so much, only because I'd had 48 loops to grind out a perfect attack strategy to convince her to hand over the crest that was key to the time machine.

It was natural for her to hold suspicions, but how could I convince her to hand it over otherwise? I-

Se Yue: Okay here you go.

Wu Shi: W-weren't you still thinking about whether-

Se Yue: As the heir to the Se family, I'm not such a poiseless weakling as to be unable to put my trust in a total stranger.

Se Yue: Wu Shi.

Se Yue: Even though I can't imagine it, it must have been exhausting to go through so many loops, right?

Se Yue: Such a thing would surely be an experience even I couldn't endure.

Se Yue: But, you've still made it this far.

Se Yue: All of this surely has a meaning.

Wu Shi: Even if... I haven't accomplished a single thing?

Se Yue: Aren't you being silly?

She slapped me on the cheek, lightly, with the palm of her hand.

Se Yue: The fact that you're still alive, now, is surely salvation to many others who no longer are.

Se Yue: What you have and haven't done are irrelevant.

Se Yue: Whether you have value or whether your life has value, those aren't relevant either.

Wu Shi: But, it took 48 peoples' disappearances for me to come this far.

Just like before, buying my own life with the lives of others...

She slapped me again.

Wu Shi: Stop slapping me!

Se Yue: I will when you stop being an idiot!

Se Yue: You're only thinking of what's disappeared, but you're not thinking of all the things you've accomplished.

Wu Shi: But I just said, I haven't accomplished anything-

Se Yue: If you weren't alive, I wouldn't have been able to learn any of this!

Se Yue: If you weren't alive, I couldn't entrust this mission to you.

Se Yue: Even if the past you hasn't done anything yet, that doesn't mean the present you is incapable of doing anything, either.

Se Yue: Even if the present you has no great deeds to their name, it doesn't mean that you can't save others in the future.

She smiles at me.

S: Have you considered, what would happen if I abandoned the time loop?

Wu Shi: Just- time would progress forwards again, right?

S: And what would happen to those who died of Lost Time Syndrome?

Wu Shi: ...

S: If usage of the Tour of Time is abandoned, their deaths will become immutable.

S: If it were you, what would you do?

S: Stop the loops and allow the deaths of 48 people to become an immutable fact?

S: Or continue to loop, knowing that every loop causes an additional person to lose their consciousness?

Wu Shi: Keep calm and think. There must be something useful that you've learned from all of this.

The outside is full of water already. I can't open the doors to escape- the pressure differential is too much.

But there's something I know that not even S does, because S is never in this room when the flooding itself occurs.

At the moment that the water fills the room, the pressure differential will equalize, and the doors will become openable.

But I have to wait for the exact right moment...

Wu Shi: I'M GOING TO SAVE HERRRRRR!

As the room fills up with water, I take a huge gulp of air and dive beneath the waves.

I swam upwards with everything I had!

I trusted the Se family's engineering- even if there'd been flooding, it couldn't possibly have caused total structural collapse of the tunnel.

At the top of the tunnel there SURELY had to be trapped pockets of air somewhere.

See? There's light up ahead.

Swim towards the light-

So, my death is predestined, is it.

Will the loops still continue after this? I don't know.

But even if they did, I wouldn't get a chance to speak to Se Yue again normally.

Because of my intervention, it had become more and more difficult for S to claim the crest from Se Yue.

If I were S, I'd definitely try to intercept the two of us at Midway Station, and prevent me from even being able to meet Se Yue.

That meant that this loop was the last chance we had.

I continue swimming upwards for my life.

Somewhere in this vast blue sea is the future that I've been fighting to reach!

Se Yue: Khhhack, gack, gah!

Wu Shi: Heya, young mistress.

Wu Shi: Thanks for all that encouragement.

Wu Shi: It has been my pleasure...

Wu Shi: ...To be able to have met you in this life.

Se Yue: WU SHI!!

Se Yue reached out to me, but at this point I was too weak to even grab onto her hand.

Se Yue: Wu Shi, don't diiiieeeeee!

Se Family Head: You are someone special.