Compared to the tidy and orderly ground floor, the private space on the top floor is quite simply Hell on Earth. A few minutes ago, Welt would never have predicted that he would find these items outside a girl's bedroom — Pizza boxes piled together like Jenga. Wastepaper piled into bins and forming trash heaps the size of small mountains. Bras, undergarments and stockings, hang-drying everywhere. Mysterious electronic devices discarded and tossed against a corner, their surfaces covered with dust. It's hard to imagine how: but perhaps because the cleaners won't come upstairs, everything has now turned into this hair-raising spectacle. Now, if there is the tiniest, most remote possibilty, that this scene is actually typical for private residences of countless single ladies everywhere — God knows how many gentlemen will be left shellshocked and heartbroken? At least, right now, Welt is searching for Room 203 with a heavy heart. “Knock Knock.” … “Click.” Somewhat surprisingly, the door opened rather quickly — No! That was the sound of a door locking! … Dr Tesla! I-I do not come upstairs willingly! Huh? Are you trying to say you're sleepwalking, Assistant Welt? From the other side of the door transmits a grumpy and energetic voice — no doubt it's the real deal, none other than Tesla herself. N-n-no, I'm not… Uh … I mean … It was Dr Einstein who asked me to come and wake you up … I wasn't asleep! Umm … Okay then … Anyway, we're going to take the next flight to America … W-w-w-wait — — To where? To America. — Now? Yes … … “America”, as in the “United States of America”? Correct … Western USA … Montana … … Have you gone mad? I don't understand the situation either! It was just that the short-sleeves — no, glasses — no, the Finn showed her a strange letter, then she immediately became all serious about it … … What the heck? Um … the letter said something about finding some ancient pasttimes … Hmm … and some words I didn't recognise … Ah, that's right! The sender's name was Sch … er, someone called Schr … what was it — — It's Schrödinger! Y-y-yes! Schrödinger, it was from Schrödinger. Planck that old hag, once again using her own students to pick up fresh meat! … Huh? You don't need to know! Um … Clearly, she's mine! … Clearly, so is Lab 42! … Clearly — The topic is beginning to sound a bit too dangerous, so Welt, standing outside the door, can only cover his ears and keep mute as a mouse. But the dreadful ringing and clattering of her shrill voice continues incessantly, piercing through the door into his eardrums. … All right! Clatter scatter. The poor young man had fallen onto a pile of pizza boxes, and is now sprawled out on his back, eyes glazed, mouth agape. The door had swung open without warning — startling Welt, who unfortunately back-pedalled onto the pizza boxes — and without much force, slipped and fell. But that is not the most important thing. T—Te — Urgh you pest! Did your fall give you brain damage as well? Move aside! Dr Tesla! It's not yet summer outside! Huh? What are you talking about? I mean, that … y-y-you … Y-y-you what? You stuttering fool. M-m-move! … You're wearing only a nightgown right now, aren't you?! And with a muffled sound, Welt's “Welt” comes crashing down, instantly transforming into a sea of white. Hnngh — O-o-ow.

Welt is seated in the front row of a temporarily-borrowed Volkswagen Beetle alongside the driver — the Finn with the gold-rimmed glasses. Welt lightly touches his head.


Sure enough, it now sports a bump.


But having said that … my life is still intact. Perhaps that alone is worth a three-day holiday?

 Squinting at the back seat through the rearview mirror, Welt spies the source of his suffering, using her compact mirror to calmly draw on her lipstick. Welt can't understand how such a person is capable of tossing her own living space into a complete shambles. It's even messier than Einstein's hairdo next to her. — And in a hurry, she had almost forgotten to change her clothes before they departed.

But perhaps more difficult to understand is this — where did she find that light billowing shawl, and fine one-piece dress? Not a single wrinkle on it. Anyone who has seen those Jenga stacks of pizza-boxes would be certain that this girl must have a four-dimensional wardrobe.

No, it should be the other way around — Whoever's seen this lovely cute girl before me, would never believe that she in fact lives in a pigsty, right?

 The young woman in question, who now appears rather neat and fresh (on the surface) begins to put away her mirror. Welt hurriedly averts his gaze. Out of the corner of his eyes, he notices the corners of the Finn's mouth curl briefly into a sly smile. … Stick to driving the car! Hey. Just as Welt was beginning to feel miserable, Einstein hands him a document wallet from the back seat. Is this … for me? Welt takes the paper wallet. Inside, there appears to be several small hardbound booklets. Mm-hmm. Open it and have a look. You'll need them later. … One of the booklets is a passport. The wallet also contains a work permit of the Imperial Institute, and some documents to guarantee movement through Immigration. Welt Joyce? Printed on the passport is one such name, half-familiar, half-foreign. Ah … Joyce is a surname taken from an author. Do you know “Ulysses”?

Note:

“Ulysses” is a novel written by Irish modernist writer James Joyce in 1922.

The novel chronicles the daily life of the protagonist — a distressed Dubliner, a salesman by the name of Leopold Bloom — in Dublin during the day and night of June 16, 1904.

“Ulysses” is a masterpiece of the stream-of-consciousness genre, and is hailed as one of the top 100 English novels of the 20th century. Each year, June 16 is commemorated as “Bloom Day”.

 Ulysses? … You mean the Latin name for “Odysseus”? No … Well … I shouldn't have expected you to know that. Just pretend I never asked. Anyway, make sure you remember the name she gave you, and avoid giving yourself away in front of Customs. Giving myself away … wait, is this documentation forged? After all, the name “Welt” was just made up by Einstein not that long ago. Well, it depends on how you look at it. Just pretend it's — “an official certificate issued by a civilian without explicit permission”. What kind of justification is that? Look, it's something we can't reveal! But if you start acting all weird, our Righteous Friends of Justice from Scotland Yard will start investigating and asking difficult questions — and I do not particularly welcome that idea. Isn't Scotland Yard a criminal police organisation?! Not the Home Office?! … Gosh, how could an amnesiac like you remember something as obscure as that? Who planted such ideas in your head? I just mean the police, okay? Any police! Erm … Relax. Just remember your name and you'll be fine. … Mm-hmm. Ah. What now? None of your damn business. Hey Finn, what did you do with your son? “Son”. For a brief moment, Welt was unable to parse the exact meaning of this word in his brain. It's fine, I've already called his school. It's not the first time Joachim has been put in such a situation. He'll be okay. Joachim. Seems like that's the name of the Finn's son … Wait. Son? So in other words, Mr Gold-rimmed Glasses here, he has a son who is already attending school? What are you doing, blanking out again? You blockhead! Hurry up and memorise your name! With a karate chop, Twintails strikes Welt's head at the exact spot where the lump is growing. Most certainly a deliberate and targeted manoeuvre. O-o-ow… Y-you, how could you be sure I wasn't busy doing that just now?! Hmph. Idiot. You're obviously envious of Finn the family man, right? Urgh … Miss “Yang”. Huh? Henrietta Yang, a young and promising archaeologist, a beauty of mixed German-Chinese heritage. She's the Finn's wife. However — — she is also a very busy lady who can only be at home for around ten days a year. How about you also try raising a child by yourself? Oh … Ha ha ha … Actually, everything's gotten much better after he started going to school. Anyway, my wife's work is valuable and deserving of our support. Whatever, your top priority now is to memorise your name. And your surname. Every single letter. Don't you dare think about anything else! There'll be plenty of time to do that on the plane! Twintails grips the back of Welt's collar, and fiercely “exhorts” him with those menacing words — before purposefully turning towards the mophaired girl seated next to her. But … that said, is it still that hard to get anyone to do anything with me? Even if it's in such a boring place as an airplane? … What now? Last time, you didn't play with me, and instead read a book all by yourself. As if your time is simply too precious to keep me company. … Mophead stares expressionlessly into Twintails' eyes. This time we're sharing a double room. … WOW! REALLY, REALLY? No single rooms this time? Hahaha, that's fantastic! I love you Liserl! Love you to death! — But only if you promise to dress properly after drinking alcohol and taking your bath … … … … S-such a tease … How could that possibly be true … Aha ha ha … … Wait, so what I saw before was really — — UWAAHHH?! Before the poor young man in the front seat could react, he was already clutching his head, groaning, and falling back into his seat. Welt, shut your trap!! The first leg from London to New York. Eight hours. Then transfer to a flight to Chicago. Two hours. Then the final leg to Billings. Another two hours. This does not include time spent waiting to board or change flights — which will be considerable despite the fact they are VIPs. With the expectation of such a long journey, the roar of the jet engine is even more sleep-inducing than usual … … Especially when the scenery outside the window is an endless monotony of vast ocean. So, even when Welt is awoken by an urge to pass urine — — For a while, he hesitated to leave his seat. He lifts the right arm of the lightly-snoring Twintails that had been draped across his body; and he helps the Finn on the other side of the aisle pick up his glasses that had fallen to the floor — — Only after stepping into the aisle does Welt notice that, among the travellers sleeping left and right, Einstein is still awake, sitting by a window and reading a book in the light. It seems that, every now and then, she is also jotting or scribbling something into her notebook. I'm going to the restroom for a while.

Understood.

 The messy-haired girl wrote on a slip of paper and held it up with her hand. Is she reminding him not to disturb other people's sleep? … Feeling embarrassed, the young man decides to get on with it and move towards the restroom. At this moment, no one is waiting in the queue, so Welt is quickly able to address his particular physiological need. Maybe I should continue sleeping to get rid of this jet lag … Why isn't Eins taking a break?

Not taking a break?

 “When in Rome, do as the Romans do.” Welt decides to hand her back a note.

I'm just reading something quite interesting.

 It is written on the note passed back to him. The temperature in the cabin becomes a little cold, and the young man cannot decide whether he should put on a coat. Naturally, Twintails is still sleeping blissfully between the two of them.

What is it?

Riemann conjecture.

Math problem?

All non-trivial zeros of the analytic continuation are on the line 1/2 + ti.

Absolutely no idea.

Not surprising. And people who lack knowledge of complex functions will find it hard to understand.


You only need to know that it can be considered the Holy Grail of the entire mathematical community.

Holy Grail?!

For example, if it holds true, from the generalized Reimann Conjecture, Goldbach's conjecture can be easily proven.


Do you know what Goldbach's conjecture is?

No, I don't …

Any odd number greater than 5 can be expressed as the sum of three primes;


Any even number greater than 2 can be expressed as the sum of two primes.

…


All in all, sounds impressive.


Do you want to solve these conjectures?

No, I don't.


They are completely beyond my abilities.


Moreover, my main business is not mathematics. It's just that Riemann had a great influence on me, that's all.

Was he your … maths teacher

You could say so.


He certainly didn't know me, and it was impossible for him to know that my general theory of relativity was based on his Riemannian manifolds.


After all, he was a historical figure from more than a hundred years ago. He was dead by the time my grandpa was born.

 It takes the young man a while to digest the general meaning of that statement. He decides to ask a question that may be a little easier for her to explain — — if only so that he can continue following the conversation. … Especially while a certain Twintails remains asleep.

General relativity?

In simple terms, it is a theory that universal gravitation is equivalent to the distortion of time and space.

…


Is there a metaphor or image I can imagine?

You must have seen a whirlpool before.


Imagine a wooden ball falling into the whirlpool. Does it look like it is sucked into the hole in the centre?

Yes.


— Do you mean that gravity is also an illusion like this?

That's right.


We know that for the wooden ball, the twisting water surface is the direct cause of its spiral motion.


The same is true for a planet.


Any object will rely on its own mass to distort the space and time they are in, forming a vortex that attracts other objects.


Gravity is just a manifestation of this distortion.


Imagine that the surface of the earth is full of such ripples, and our plane is surfing on it.

This feels like some kind of philosophy …

Physical theory without mathematical notation is philosophy.


That's why Sir Newton's masterpiece is called “The Mathematical Principles of Natural Philosophy”.

I haven't read that book …

You won't find it easy to understand.


The mathematical notation of that era is itself indecipherable for most modern readers.

Indecipherable …


Speaking of which, what was that weird text in Schrödinger's letter that I couldn't understand?

A name.


The name of an information processing device from 50,000 years ago.

 The content of this sentence is so unexpected that Welt remains perplexed for a while.

What?

 The other party simply draws a line silently under the words “information processing device”.

So … what is an “information processing device”?

Imagine a librarian made of machinery, or a library with automatons as its administrators.

… Automatic machinery?


… Fifty thousand years ago?

From your perspective …


Just treat it as a cliff-hanger, a taste of things to come.


☺

Please tell me now.

Too much trouble.

Please.

Someone will tell you in due course.


Someone whom I reckon will not be afraid of this inconvenience — so please spare me the trouble.


☺

Whoa, Eins is so mean.


☹

Of course I am.


p.s. Now that I think of it, I find your tone pathetic.

 The young man had no choice but to stick out his tongue. The girl responds in kind. While doing so, she also takes the note back from him.

Let's use this opportunity to attend math class.

… Are you serious?

Of course.


Do you know how to prove e^(πi) + 1 = 0?

How could I know?!

Oh. Should we start with the fundamental theorem of calculus?


No, since I need to teach you, maybe it's better to start by learning Dedekind cuts?


Ah, at this point, I think we're better off just starting from the very basics with set theory …

… Can I choose to sleep?

Okay.


Then I can read more books by myself.


☺

 And as she passes the note, the girl sticks out her tongue with an even more innocent expression. It is as if she is saying — “Want to chat with me? You're a hundred years behind.” … … … Countless people killed. Countless buildings, the pride and joy of those very people, incinerated and destroyed. I have long since grown numb to their desperate wailing. Now, these survivors, like cockroaches … How are they going to deal with me? Eviscerate me live, cut out my Herrscher Core, then hang me like a dog in public? … … … HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA! Quite interesting, isn't it? A strange weapon that can distort space-time and create blackholes, is that the way it gains its power? So marvelous … And you lot can unleash its power as often as you like … … But one day, it will use power a hundred-fold stronger than I am now, to seek vengeance against you! HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA! And when that time comes, I really hope you won't lower me from the gallows — — in that case, won't it be a perfect time and place for me to witness with my own eyes, the miserable demise predestined for you? HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA! … … … … … … Awakened by that crazed laughter, Welt sits weak and limp in his seat, his mouth wide open and gasping for air, the blue veins of both temples twitching and pulsating. That nightmare just now, it felt much too real — so real that Welt begins to wonder if it was a flashback from his true memory. “Herrscher”. Welt had heard this term before while he was in the previous labs. According to conclusions drawn from ancient manuscripts, when the instantaneous power output of a Honkai eruption reaches over 1000HW, there is a chance for an existence called a “Herrscher” to be born within the disaster zone. The “Herrscher” is a monster transformed from a human who is highly adaptable to Honkai Energy — — These women can use the supernatural power originating from the “Core of the Herrscher” to destroy the human world with impunity. Yes, “women”. More than a dozen Herrschers had been recorded in ancient literature, and with no exceptions, all of them were female. Generally speaking, the adaptability of males to Honkai Energy is much lower than that of females — and the Herrscher is the ultimate manifestation of that adaptability. … There are no Herrschers in the world today. Also, those various statements referring to them in ancient literature may be nothing more than crude creation myths. But one thing continues to make the young man Welt feel uneasy: in his dream, the woman whose form he had taken, why were her thoughts so chilling and frightful? Zzz … Zzz … Zzz … Looking to his left and right, he sees his companions all immersed in their own personal dreams. … Don't think too much, a nightmare is just a coincidence, a stroke of bad luck, nothing else. Motivating himself in this way, the young man takes a deep breath, and closes his eyes. Just go back to sleep, and wipe my mind clean of that terrible figment of my imagination. New York International Airport. Due to the flight spanning five time zones, Welt can still see the afterglow of a setting sun here, even though it has been ten hours since lunch. Dr Einstein, Dr Tesla. Two strangers suddenly interrupt Welt's reverie. Excuse me, who might you two be …? The Finn stands vigilantly in front of the two ladies. Dr Einstein, we should have met before. This middle-aged man has a deep voice. Welt feels as though he too had heard his voice before. What can I do for you? The mophaired girl responds emotionlessly, as if they had never been acquainted. The Old Man hopes this will be of help to you. The middle-aged man takes a scroll case from his leather briefcase, and hands it to the Finn. You are an expert in ancient manuscripts, right? For the time being … Then you should recognize this. … The Finn opens the wooden box dubiously, and pulls out a tattered piece of parchment that appears to have only been recently restored. Aramaic … “Judgement Day” … “Sacrifice” … “Song” … This verse … C-could this be the Dead Sea Scrolls? Hehe … indeed you recognise it. Not bad. This is part of the scroll that has never been released publicly. I hope that the secrets within will be useful to your research. So, the Overseer, what exactly does he need us to do? Nothing. The Old Man just hopes to give Lab 42 a hand in their research — that is all. In other words … He has high expectations for our research this time, yes? Of course. He looks forward to reading your thesis. Okay, okay, I understand. The point of our activities here is to not let the North American branch monopolise the results, right? To muster people and mobilise resources for such a trivial reason, relations between the European and North American branches must be quite sour indeed. … Ah yes. Here's a souvenir, please kindly accept. The middle-aged man no longer pays any attention to Tesla, but instead takes out a box of luxurious-looking chocolate from his leather briefcase, and hands it to Einstein. Well, see you next time. … Tut. That man liked to talk around the point, but I could tell that they still have that same old authoritarian streak. After all, the tail cannnot be allowed to wag the dog, and a tree trunk must remain strong while its branches remain light. Now that a new branch finally prospers, they have come to fear it. And so they turn against it faster than turning the pages of a book. … Einstein remains non-committal in her non-response, and silently peels away the wrapping paper from a piece of chocolate. Hey! I'm speaking to you, Mophead! Just a box of chocolate is enough to win you over?! If I don't eat it, Mr Cocoa Farmer will be upset. … Are you even listening to me?!