The herbal tea arrived in transparent glass cups, looking incredibly stylish.
Just as Fia-sensei had mentioned, it carried a scent reminiscent of apples. When I took a sip, the flavor was subtly sweet and refreshing, making it easy to relax.
"It has such an elegant, relaxing flavor."
"The herbal cookies are delicious too. Here, Miyama-kun, say 'ahhh.'"
"Eh?"
Fia-sensei held out a cookie toward me in one smooth, natural motion. Caught off guard by the sudden gesture, I reflexively glanced around at our surroundings.
There were a fair number of customers in the cafe. While it wasn't as if we were the center of attention, I still felt a bit self-conscious.
"E-Err, ahhh..."
"There we go!"
Fia-sensei's smile was far too dazzling to refuse, so I eventually opened my mouth and accepted the herbal cookie from her hand.
The crunchy texture combined with the refreshing coolness of the herbs was pleasant. Just as I was thinking that, Fia-sensei opened her own mouth as if prompting me to return the favor.
"Ahhh."
"...Here you go."
"Mmm, delicious!"
Fia-sensei really was proactive; once she decided to do something, her follow-through was incredible.
"How should I put it... you seem to be having a lot of fun, Fia-sensei."
"Yes, I am. I’m just so happy that I could become your lover and spend time together like this. I want to do all sorts of things that couples do."
"I'm a little worried about people watching us, though..."
"Really? I'd actually rather show you off to everyone. I want to say, 'Isn't he wonderful? Isn't he handsome? He's my boyfriend!' you know?"
...What was I going to do? Fia-sensei was incredibly cute. While she had the air of a mature woman, she also showed this mischievous side, and above all, her smile was more radiant than ever.
Being approached with such unreserved affection naturally made me embarrassed... but more than that, it made me feel happy.
"Fia-sensei, would you like another one?"
"Ah, yes! I'd love one."
"Here, go ahead."
"Ahhh."
For the moment, I decided to set aside my embarrassment and simply enjoy Fia-sensei's lovely smile.
After leaving the cafe, we traveled using Fia-sensei's teleportation magic to complete the stamp rally. As expected, teleporting made the process incredibly fast, and we were able to finish visiting all twenty locations in no time.
Carrying the sheet with all the collected stamps, we went to the shop of the organizing merchant association as indicated on the map. There, we were handed an envelope containing a difficult quiz along with a small participation gift.
The clerk explained that if we could solve the puzzle, we should return to the association and provide the answer to receive a super-luxury prize.
Incidentally, the participation gift was a fairly well-made pen that looked like it would cost a decent amount of money. If that was just the consolation prize, we could probably have high expectations for the actual reward.
Stepping outside, I looked at the paper with the problem on it together with Fia-sensei, but...
"W-What is this? Just a long string of numbers... is it some kind of code?"
"Hmm, I have no idea how to even begin solving this. There aren't any hints, either..."
The paper in the envelope was covered in numbers that looked to be over a hundred digits long, with absolutely no other information provided.
Thinking it would be impossible to solve as it was, I turned the page over.
"Ah, there's something on the back. 'Hint One: It indicates a location'?"
"We can't tell anything from just that. Hint Two is... ah, it says 'to be announced at a later date.'"
Only one hint was written on the back, and it seemed that any further clues would be announced at regular intervals if no one produced the correct answer.
The announcement for the second hint was scheduled for tomorrow.
"Yeah, I'm completely stumped. Shall we try again when the next hint is announced?"
"I'm not very good at this sort of thing either. Hmm, coming all the way back here over and over would be a bit of a hassle, and it doesn't look like I could solve it even with one or two more hints. Let’s just give up for today."
"You're right. It’s a shame, but..."
Just as expected of a "super difficult problem," I truly had no clue. Right as I was talking with Fia-sensei about throwing in the towel, Alice suddenly appeared and snatched the paper from my hand.
"Let's see... Hmmm, the answer is 'Sky Castle.'"
"Eh?"
Looking at the paper for barely a second, Alice declared the answer to be Sky Castle. From her tone, she hadn't already known the answer; she had clearly decoded it just now.
"Alice, you actually understand this?"
"There are slight gaps every seven digits. If you divide the string into blocks of seven, you get twenty sets of seven-digit numbers, which matches the number of stamps in this rally. If you divide those numbers by the section numbers—the addresses where each stamp stand was placed, in order—then add all the resulting numbers together, multiply that sum by the Sinfonia Kingdom's founding day, and split the result into the number of digits required for world coordinates, you'll end up with three specific points. Those are all coordinates around the Sinfonia Royal Capital, and if you connect those three points with lines on a map, Sky Castle sits right at the center."
"Just what kind of brain do you have...? Wait, you solved that with almost no hints?"
"Well, I checked about 480,000 other patterns just in case, but since nothing else seemed plausible, Sky Castle is definitely the answer. Well then, I'm off."
As expected, Alice was brilliant—or rather, her mental processing speed was beyond human comprehension. Seeing something like this made me realize her greatness all over again.
"Uhh, she ended up just giving us the answer..."
"The fact that Shaltier-sama went out of her way to tell us the answer suggests that the luxury prize might be something useful for us."
"Ah, that's true. It wouldn't be surprising if Alice knew what the prize was. Though it seemed like she really did just solve the code on the spot..."
"It probably wasn't much of a challenge for Shaltier-sama. She truly lives up to her reputation as the greatest brain in the three worlds."
Anyway, since Alice had gone out of her way to appear and provide the solution just as Fia-sensei said, there was a high possibility that the prize was something beneficial. We decided to head back to the association and give them the answer.
Serious-senpai: "I have one question: can regular people actually look up world coordinates?"
???: "Books containing world coordinates are kept in libraries and similar places, and if you learn the calculation methods, you can figure them out just by looking at a map. Most people who excel at teleportation magic keep those formulas in their heads."