I stared at the clocks, each ticking away at a different pace, and sighed while massaging the bridge of my nose.
Man, my head hurts...
"I considered the possibility... but seeing the proof right in front of me is something else entirely."
Shaking my head, I looked once more at the clocks placed on my desk. Specifically, I looked at the desk clock that had been inside the dungeon—the one that was now about ten minutes ahead.
"So the speed at which time passes is different inside and outside the dungeon."
I picked up the advanced clock, narrowing my eyes and frowning.
I had started this as a simple preliminary investigation, but things were becoming incredibly complicated.
"For now, I'll place the clock in the dungeon a few more times for further verification. I need to at least confirm exactly how much of a time difference there is."
I pulled a notepad from my desk drawer and recorded the current times shown by the two clocks. For the record, the time difference measured during this attempt was ten minutes and twelve seconds.
"...Alright, let's do this."
I reset the clock to the correct time, placed it back inside the dungeon, and slowly closed the drawer that served as the entrance.
After finishing my fourteenth verification test, I retrieved the clock, closed the drawer, and let out a long breath.
"I see. So the time difference only occurs while the entrance is closed..."
I muttered to myself while looking at the display on the retrieved clock.
From the tenth test onward, I had left the clock inside the dungeon with the drawer open. No matter how many times I tried that, no time difference occurred between the clock inside and the one on the desk. In other words, I had discovered that the time dilation was linked to the opening and closing of the drawer—the dungeon's entrance.
"Meaning, when the drawer is shut... when the entrance is sealed, the temporal connection to this world is severed..."
My thoughts trailed off as I stared at the drawer with distant eyes. The flow of time was different. That meant, at the very least, this dungeon existed in a universe separate from our own—or perhaps within a sub-space.
I only had a superficial understanding of the subject, but apparently, time generally flows at the same speed within the same universe. There were exceptions, of course, such as moving at near-light speeds or being near super-massive gravitational bodies like black holes, where time would slow down. However, those phenomena didn't apply here. After all, I was just sitting in a chair in my room.
"Which means... rather than simply thinking of this drawer as an entrance, it's probably more accurate to view it as a transfer device leading to a different universe or sub-space."
From the perspective of a sci-fi novel or anime, it might be best to think of this Slime Dungeon as an artificial world created in an alternate dimension. Creating a sub-space for a specific purpose was a common trope. But a dungeon existing in a space where time was intentionally accelerated... This place was getting more suspicious by the second.
I cast a dubious glance at the drawer, a conflicted expression on my face.
"Well, it's not like the dungeon being suspicious is anything new. No point worrying about that now. More importantly, this is the real issue."
I looked away from the entrance and picked up the notepad covered in my measurement results.
"When the entrance is closed, time inside moves roughly ten times faster. What am I supposed to do with this?"
I tossed the notepad onto the desk in exhaustion, then leaned back into my chair and stared up at the ceiling.
"Sigh... This makes it even more impossible to go public with this dungeon."
A dungeon where time accelerates when the entrance is closed... Its value as a resource site where rare drop items could be easily harvested was one thing, but the sheer value of time acceleration was immeasurable. If the time inside accelerated tenfold when the drawer was shut, it meant one could achieve ten years' worth of technological advancement in a single calendar year.
"If I gave this information to the government, they'd confiscate the dungeon without hesitation. In the worst-case scenario, they might even try to silence me to keep the secret..."
I didn't want to believe my country's government would go that far, but considering the value of this dungeon, it wasn't an impossible future.
Ever since dungeons appeared across the globe, every nation had been pouring its resources into researching dungeon-derived technologies, desperate not to fall behind. In this transitional era, knowing that something exists which provides a ten-year advantage in just one year would make anyone do whatever it takes to seize it.
As exemplified by Moore's Law in the computing world, technology develops exponentially over time. Particularly recently, with the advancement of AI (Artificial Intelligence) technology, this technological acceleration was becoming even more rapid.
"Time might also accelerate inside other dungeons if their entrances are closed, but with the current state of exploration, there's no way to confirm that..."
I sat up and performed a search on my computer. I opened the Dungeon Association HP to check the progress of explorations for the dungeons they managed. There were dozens of such dungeons across the country, but only a handful had been explored past the 30th floor.
Of course, this didn't include government-managed dungeons occupied by the Self-Defense Forces, but I hadn't heard any rumors of those dungeons being conquered yet either.
"Well, when it comes to controlling the opening and closing of an entrance, it's probably like the transfer device—you can't do it unless you conquer the dungeon and take control of the central hub, like the Dungeon Core..."
I scratched my head in annoyance, remembering the settings of the transfer device I'd found near the entrance. Currently, I had no way to verify if other dungeons behaved the same way.
As it stood, my room's dungeon was the only one confirmed to have this property. Good grief, the trouble just keeps piling up.
I picked up the notepad and tucked it away into my Spatial Storage. It would be a pain to explain if Mika accidentally saw it.
Standing up from my chair, I stretched to loosen my stiff muscles.
"Yeah. I'm exhausted. I'll end today's investigation here. Time for a bath."
After tidying up the cardboard and the empty clock boxes, I grabbed a change of clothes and headed for the bathroom.
I woke up to the sound of the alarm on my smartphone.
"...Morning already?"
Feeling the sunlight streaming through the window, I rubbed my bleary eyes and sat up in bed, letting out a long yawn.
"...I'm still sleepy."
Because last night's findings were so shocking, I didn't feel rested at all. Shaking my sluggish head, I left the room and headed for the washroom.
"Phew... That's better."
I washed my face with cold water and finally felt awake. My brain was still turning a bit slowly, but it would have to do.
After drying my face, I stepped into the living room.
"Good morning."
"Hm? Oh, Daiki. Good morning."
"Good morning, Father."
As I entered, Father—who was sitting on the sofa drinking coffee and watching TV—noticed me and greeted me back.
That's rare. Father hasn't left yet?
"You're taking it easy today, Father. Will you make it to work on time?"
"Yeah, it's fine. I don't have any meetings this morning."
"Huh, I see."
After a brief exchange with Father, I spoke to Mother, who was in the kitchen preparing breakfast.
"Good morning, Mother."
"Good morning, Daiki. Breakfast will be ready in just a moment."
"Got it. Oh, I'll take some coffee."
After getting Mother's permission, I poured some of the coffee remaining in the pot. It was a bit lukewarm, but I didn't mind.
I took the cup and sat down across from Father.
"Hm? What's wrong, Daiki? You look quite tired..."
Concerned by my lack of energy, Father set his coffee on the table and spoke to me.
"It's nothing, really."
"Is that so... Perhaps preparations for the sports festival are becoming a burden?"
"They're tough, but the work isn't so busy that the exhaustion would carry over like this. I'm fine."
To be sure, I was mentally drained because of the mascot costume incident yesterday, but that wasn't something that would haunt me today. The real culprit was the dungeon's time dilation problem.
I appreciated Father's perceptiveness and his concern, but since I couldn't explain the actual reason, I just gave a vague smile and took a sip of my coffee to dodge the subject.
"I see... Well, the sports festival is coming up soon, so be careful not to overexert yourself or get injured, okay?"
"I will."
While Father and I were talking, the living room door opened and a sleepy-looking Mika walked in.
"Good morning, Mika."
"Good morning..."
When Father spoke to her, Mika gave a small yawn in response.
Mother, watching from the kitchen, chimed in.
"Mika, breakfast is almost ready, so go wash your face."
"...Okay."
Mika gave a mumbled response and headed for the washroom while rubbing her eyes.
After she left, Mother spoke to me and Father.
"Dear, Daiki. I'm setting the plates, so please take your seats."
"Alright."
"Got it."
Father and I stood up, carrying our empty coffee cups to the table.
After finishing breakfast as a family, Mika and I returned to our rooms to get ready for school. I changed into my uniform and checked my bag for my schedule and textbooks.
Then, I pulled the notepad out of my Spatial Storage.
"What should I do...?"
I stared at the notes on my desk with my arms crossed, agonizing over how to tell Yuji and Hiiragi-san about what I'd found. Should I tell them the truth right away—that time inside the dungeon accelerates—or should I wait until I've conducted more thorough tests?
After a moment of thought, I decided it was better to share what I knew so far.
"Even if I do more tests, there will be fewer blind spots if I get their input first."
I glanced briefly at the drawer, then put the notepad back into my Spatial Storage.
"Alright. Time to go."
I heard Mika leaving the room next door, so I grabbed my bag and headed out. When I reached the living room, Mika and Mother were sitting on the sofa watching TV.
Wait, where's Father?
"Where's Father?"
"Your father already left."
"Already?"
"He left about five minutes ago."
"I see..."
Apparently, Father had left while I was getting ready. I didn't think I'd taken that long, but I must have spent more time than I realized agonizing over that note.
I scratched my head, feeling a bit disappointed. If I'd come down just a little sooner, I could have seen him off.
As the three of us watched the TV, Mother suddenly spoke up.
"Oh? Say, you two? Isn't it about time you left? If you relax too much, you'll be late for school."
Eh?...Ah!
When I checked the clock, the hands had already passed our usual departure time. Mika and I glanced at each other, then hurriedly grabbed our bags and rushed to the front door.
We'd definitely lost track of time.
We're off!
"Be careful out there!"
Seen off by Mother, Mika and I headed out for the day.