"Welcome. Thank you very much for coming to visit... It has been a while, Prince Cecil."

"Thank you for inviting me. Yes, it's been a while, Lady Bertia."

It's Lady Bertia's tenth birthday.

During the past three months, I was unusually busy with a lot of different things and was unable to meet her. On finally meeting her, I notice that she seems a little... worn-out.

"What's the matter? Are you feeling ill?"

Preparations for her party are underway at this very moment, although only a small handful of family friends will attend it. Right after this, she'll be the star of the party.

As I volunteered to be her escort as her fiancé, I came to the Noches mansion a little early. But by the time I arrived, she had already gotten ready for the party.

She was wearing a faded gold-coloured or perhaps milk tea-coloured dress that closely resembled my hair colour. It looked a bit mature on a ten-year-old girl. In direct contrast to her charming clothing, her expression was clouded – she seemed somehow tired.

Despite this, fire blazes in her eyes as she glares at me resentfully.

"Your Highness, you're terrible!" she bursts out resentfully - immediately after we sat across each other in the drawing room and greeted each other.

"What?"

I am technically the crown prince, so normally, if someone said something like that to me, all the adults around me would go pasty white... but the only people in this room other than us, Zeno and Lady Bertia's two maids, have already gotten used to this. They nonchalantly prepare our tea for us.

Naturally, the black fox curled up on her lap continues to sway its tail at an even tempo.

"Lady Bertia, did I do something to make you twist your lovely face so?" I ask, cocking my head to the side.

"Argh! Argh! Argh!" she shouts suddenly. She picks up a cushion next to her with both hands and begins slamming it against the sofa.

It's a simple way to let out your temper in a way that doesn't harm others. It's additionally an incredibly easy way to demonstrate your anger.

... Though the black fox-lookalike on her lap doesn't seem too happy about this turn of events.

"... Ahem. Excuse me."

I drink some black tea that her maids prepared, waiting for her to calm down. But she calms down in just around thirty seconds. She returns the cushion to its original position, looking awkward, and turns back to face me. She coughs.

"B – but, your Highness, you're in the wrong as well. Just like we promised, I haven't talked about 'the past' with anyone but you. So – so – the only person I can talk to about my mother's situation is you, your Highness, but I haven't been able to see you for three months! It's my birthday today! Originally, my mother would have passed away by now! I wrote you so many letters while we couldn't meet, but all you would say was 'It'll be fine,' – I didn't know what I should do..."

... Her maids and Zeno are listening in as hard as they can, but apparently they don't count as 'people listening to the conversation' in her mind.

Well, a maid good enough to be employed in the House of Noches probably wouldn't reveal her master's murmurs and secrets to others, and my 'envoy' has reported that in fact no one has revealed such things, so it'll probably be fine.

As I muse about such things while listening to her grouching, she finally begins to cry, large tears dripping from her eyes.

Even I panicked a little at the sight.

After placing my tea on the desk carefully in order to not make a sound, I make my way to her side fairly quickly and softly put my hand on her back.

I do feel like we're a bit too close for an unmarried man and woman, but she is my fiancée – it's probably fine.

More importantly, I need to comfort her.

"Lady Bertia, I'm sorry. I hadn't thought that you would worry so much about this. I'm really fine – that's why I wrote that I was in my letters. I just was a bit busy dealing with cleaning up some accidents and planning out how to best use some leftovers and covering things up and so on. And making your birthday present took me some time too..."

To be honest, the letters she sent me didn't contain any information I hadn't already processed, so I didn't really have anything to say but 'It'll be fine,'... but from her reaction, I've caused her to worry quite a bit thanks to my short responses.

It's not the first time that I've caused people to worry like this because I just say that I'm fine if I think the future seems okay. I forget that people may not see the same future as I do.

I think it's pretty easy to see the future if you make some logical deductions based on various bits of information... but it seems that depending on the person, it may not be that easy.

When I dismiss something as something I already know and sum it up in a few simple words, it looks like sometimes I still need to say more.

This seems like a bad habit of mine.

I need to be careful.

"What do you mean, 'fine'!? Since we're changing the plot anyways, I tried to obtain as much Ruona grass as possible in order to save as many people as possible, but I don't have anywhere near enough! ... And it was difficult for me cultivate or preserve a lot of them that well so there's a lot that can't even be used for medicinal purposes. And also, the disease outbreak that should've been happening isn't, and my mother, who should've died by my birthday, is doing just fine. I just don't know what's going on... I don't know what I should do!"

"Ah, hey, Lady Bertia. Don't cry so much. It's fine."

"It is not fine!"

"It's fine. The disease outbreak happened, just like you said... it's just that since you gave me information, I was able to deduce what kind of disease it was and what kind of medicine to make as well as where it would begin spreading. So it's just that I made the medicine before the outbreak happened, and when it did, I quarantined the patients at the source for treatment, so there were almost no deaths or casualties."

"There's no way that making the medicine and quarantining the patients at the source for treatment would be fine... huh? Medicine? Quarantines at the source? Treatment?"

"That's right. So the disease has already been put under control – it's unlikely it will infect your mother. Oh, but just in case, here's the medicine. I thought it would be a good idea to bring it to be prepared for a worst-case scenario."

I take the medicine from Zeno, who had been waiting next to me for the right moment to give me the medicine. I place it in her hand and have her grip it.

"Medicine? What? Huh? What? Wait, I don't understand..."

"See, that's why I said it would be fine. This way, there won't be many deaths due to an outbreak in the capital, nor will your mother die."

"Huh? Wha-a-a-a-a-at!?" cries Lady Bertia, opening her tear-filled eyes wide.

Oh, one of the maids quietly headed out to the hallway to deal with the people who would no doubt come at the sound of Lady Bertia's scream.

Yes, truly an excellent maid.

"W – wait a second, your Highness! What does this mean!? Please explain!"

Looking surprised or perhaps panicked, she grabs my shoulders and shakes me back and forth violently.

... I've never been treated like this before.

But my head is spinning – this isn't a very nice experience.

"I understand already, so shall we calm down for now?"

With a bright smile, I grip both her wrists and stop her from shaking me.

"As if I could calm down! Hurry up and explain!"

She looks like she's about to bite me. Good grief, I think.

I tell her about what happened after she told me about her mother's future death.

After her story, I asked my father in order to receive permission to use the greenhouse and Ruona grass seedlings.

As it was apparently difficult to cultivate, I read books that described how to cultivate it. I additionally used some of my own ideas based on Ruona grass' peculiarities as a plant... and it grew unbelievably well.

Since I had grown it so very easily, I thought that I might try my hand at making the medicine as well. I asked my father to hire doctors of pharmacy and medicine in order to learn from them. As I learned under them, I read every book I could get my hands on in the royal library.

I had Lady Bertia tell me everything she could recall about her mother's symptoms when she died as well as any peculiarities of the disease in order to narrow down my deductions as much as possible.

... Though she had apparently been simply asking me for advice over tea and hadn't really thought that I would begin to seriously make my move.

After thinking hard about those symptoms along with the most statistically likely infectious diseases to occur based on the weather and climate this year, I eventually narrowed it down to a single disease.

And from her comment that the disease was an evolved form of a known disease and the fact that Ruona grass was needed for the medicine, I tried making the medicine through trial and error.

It's much simpler to reverse-engineer a known solution than to determine a single answer from a large number of possibilities. So I reached the solution remarkably easily.

Though well, I couldn't verify whether my solution was truly correct or not until the outbreak already happened.

Anyways, the point is that it took quite a bit of time for a simple prince like me who was no scientist to get this far, but things went pretty well up until then.

... That's right, until then.

Though I had more-or-less determined the disease and how to make its medicine, it was a deduction that all hinged on believing Lady Bertia's story.

I had made my move out of curiosity, thinking that I didn't really care whether or not it was true. But the adults around me wouldn't do anything for a reason like that.

I didn't have the necessary tools to convince them and nor did I have the guts.

And so out of desperation, I decided to create some coincidences.

I, a prince, claimed to coincidentally be interested in infectious diseases and visited a doctor researching them under the pretense of learning from him.

There, I talked passionately about the potential effects of Ruona grass and their use, which I had coincidentally gotten into growing.

The doctor listened intently to my story perhaps partly because I was the crown prince.

At time to time, we entered into back-and-forth discussions to exchange ideas.

However, it was difficult moving forwards from there.

It was much more difficult than I had imagined to lead him on a round-about way towards the answer without revealing that I already knew it.

I experienced how painfully difficult it was to manipulate someone to where you wanted them without them noticing.

I lost count of how many times I wondered how he couldn't notice something this simple.

Regardless, I doggedly continued our discussions until I somehow managed to give the doctor all the information necessary to make the medicine. All I needed to do was make sure that he would make the connection between the medicine and the disease when the time came.

All I needed was for the doctor to notice the disease as early as possible once he had finished all the initial preparations.

After all, the infectious disease that was most likely to spread this time around was his speciality.

I presumed that in front of a patient, even if their symptoms were slightly different, he would identify the correct disease. The disease was most likely to enter the capital through the main gates – which could also be called the entranceway to the city. And so since there coincidentally happened to be an empty room near the gates, I asked my father to make his temporary home in the capital be there.

And so I had everything prepared by the time Lady Bertia had said the incident would occur. I had successfully reached a situation where all I had to do was watch my plan unfold.

Well, it might be a bit odd to say this after I did all that, but to be honest, at that point I didn't even half-believe Lady Bertia's stories of the future.

It's just that I had thought that even if the chance that an infectious disease rampages through the capital was slim, it would be a good idea to be prepared. I had been able to learn a lot through this incident as well so a part of me was satisfied with just that.

That's why I was shocked when I visited his home to see someone suffering from what looked like the initial symptoms of the disease. I had snuck into his home on the pretext of wanting to see his medical texts, wielding my childish innocence as a weapon.

Stuff like this really happens, I thought.

But though I did think that, since I had already made all the preparations, I didn't really panic.

All I had to do was coincidentally connect the dots and manipulate events to make a 'miracle' happen.

The doctor really worked hard once he realized that a patient with a new strain of infectious disease had appeared.

Naturally, I provided him with my large supply of Ruona grass which I had been coincidentally growing as a hobby.

In this way, everything unfolded just like I had planned.

This happened just around two or three months back.

"Wa – wa – wait a second, please! Your story is weird in a lot of places!"

"Is that so? In which places?"

After telling Lady Bertia about everything that happened after she told me about the infectious disease – about how I discovered a patient, about how I had the doctor realize how to make the effective medicine and had him actually make it, about how I quarantined the disease before it could really spread and treated it – she cried out while holding her head in her hands.

She's saying that my story is weird, but things unfolded just the way I planned – I don't think it's really that weird?

Oh, by the way, I obviously didn't mention that I hadn't really believed her until the first victim appeared.

Putting aside my personal beliefs, in the end, I started to move based on her story and succeeded in protecting the citizens of this kingdom from the terrifying disease that she had predicted.

There's no reason for me to go out of my way to be stupidly honest and reveal everything. That would just make her think less of me.

"W – w – why would you do such a thing, your Highness!?"

"Did I not say that I would help you?"

"You did say that. However..."

"Additionally, I have no intentions to ignore my own fiancée's worries, nor to overlook the possibility that the woman who will become my second mother could die, no matter how slim that possibility may be... especially if I can deal with the issue if I put a little effort into it."

"That definitely was not a 'little' effort. Normally, an eleven-year-old child wouldn't be able to do something like that."

Lady Bertia looks at me with a complicated expression, like she can't tell whether she should be happy.

"Hm? I'm almost twelve, you know?"

"A twelve-year-old too!"

"Well, a normal twelve-year-old probably couldn't. However, remember, I'm the crown prince. I've received quite a bit of education and I can use the books in the royal library as I please to a certain degree. For the first time in a while, I spent entire days engrossed in my books, but that was beneficial to me and fun as well. Oh, and I can also borrow other people's help if I get Father's permission, though it's not like I can use people as I please."

Though well, since there were a few too many 'coincidences' this time around, Father is probably a little suspicious since he knows the whole situation. But if I just insist that it's "just a coincidence" with a smile, he'll probably let it go, look tired, and mutter "good grief".

"I – is that so?" says Lady Bertia, looking at me with an astonished expression.

I respond with a bright smile.

Behind me, I feel like I can hear Zeno murmuring, cheerful as usual, that even a normal young crown prince wouldn't be able to do something like this. But I decide to ignore him.

"It's possible, perhaps? It's possible for things to work out so nicely, perhaps? It shouldn't be, right!? It shouldn't be, but it is!? Wait, but for the 'Android Prince' who's the embodiment of a genius, maybe it is possible? But but..." murmurs Lady Bertia in front of me, hand on her chin as she begins to worry.

... What does she mean by 'Android Prince'?

As I expected, I can't understand what she's saying again today.

"Well, don't sweat over the small details, okay? It seems like the Lord and Lady Noches are fine as well and the damage to the capital was minimized. Isn't that good?"

"... T – that's true! It's good that Mother and everyone in the capital were able to escape from the disease's evil grasp!"

Lady Bertia decides to stop thinking. Perhaps she thought too much and reached her limit.

Yeah, this is more convenient for me too.

After all, even if someone asks me why I was able to do something like that, the only answer I can give is that I was able to do it when I tried.

"Oh, that's right, Lady Bertia - I'm planning to give you your official birthday present from the King and the crown prince later, but unrelated to that, I have something for you from me personally..."

Though she decided to let things go, it seems like some things are still bothering her. I hold out a velvet-covered square box to her.

It was about the size of both my hands put together. Naturally it didn't fit in my pocket, so I had Zeno hand it to me right before I gave it to her.

"W – what is this?"

Despite deciding to let things go, it looks like she's having a tough time doing just that. She looks at the box I hold out to her cautiously, with an expression like she has something stuck in her teeth.

Her expression makes her look like she's about to burst out saying "You still have more surprises for me!?"

"It's my personal birthday gift to you. Though it's handmade, so it's nothing special," I say, opening the lid of the box and showing her the inside.

"My! It – it's splendid!"

It's an exquisitely designed necklace that looks like silver ivy is tangled together in the form of a necklace. It's adorned with an ultramarine blue heart-shaped stone, the colour of the night sky on a clear day.

Though well, in reality it isn't a 'stone', but rather a carefully cut glass bottle containing an ultramarine blue liquid.

"This is some of the leftovers from the cure for that disease."

"What? Leftovers... of the cure?"

Confused, Lady Bertia tilts her head nearly horizontally to the side.

"That's right. While I was researching Ruona grass in order to make the cure, I learned that it has the ability to increase the effectiveness of other medicine. However, if you just use it as it is then it's not really well-suited with some medicines, so the ones it can improve are limited. Apparently the base medicine for the medicine we used this time around was well-suited with Ruona grass, so the medicine turned out good."

As I explain, she listens while nodding her head in agreement.

However, it's a mystery to me whether she's nodding her head because she really understands.

"But while I was looking through the royal library's books to see if I could use Ruona grass for other