Yes, that was back when I had just arrived in this different world. As soon as I passed through the door into this world, a strong-looking orc appeared, trying to enter the great mage’s house.

At that time, I had no understanding of the strength of this barrier magic at all. In an attempt to drive the orc away, I attacked it using the power I had inherited from the great mage. Of course, I had no clue about controlling my strength back then, so I unleashed an advanced-level spell, the second strongest after an ultimate magic spell, and turned the orc to ashes.

“...If I recall correctly, it was around this area.”

“I see... If it was an advanced spell backed by the master's power, then it makes sense that this barrier magic would be damaged.”

The damage to this barrier magic was entirely my fault. Even for a brief moment, Ande had gone to the other world, and I had feared that the door would disappear. Now I feel embarrassed for thinking that.

“What happens if this barrier magic is destroyed!? Will the door connecting to that world disappear immediately!?”

“...No, I don’t believe anything will happen right away. The part that was damaged this time is the function that absorbs magic power. Over time, its ability to take in magic will weaken, and once it can no longer sustain the magic power linking the barrier magic and the door, both will disappear. That is my assumption.”

...Uh, in simpler terms, because I damaged this barrier magic, the door and the barrier magic itself will eventually disappear. ...This is bad. What do I do!?

“Isn’t there anything we can do!? That’s right, what if we use magical tools or magic stones to supply it with magic power—”

“Unfortunately, it seems that the construction formula of this barrier magic and the door to another world is a single integrated system. We cannot insert an external source of magic power.”

“Then, what about fixing the damaged part of that construction formula or whatever it is?”

“For that, I have been going through the materials left behind by my master and studying the barrier magic and the door to the other world in detail. However, it is beyond my ability for now. I will continue my investigation, but I do not know how long it will take... No, rather, you should assume that no matter how much time I spend, the chances of being able to repair it are quite low.”

“That... can’t be...”

The door to the other world will be closed. I will no longer be able to travel between my original world and this one. That would mean I would never be able to see Sara, Lilith, or the others ever again...

“I, too, am very interested in Masayoshi’s world. Besides, this is the final magic left behind by my master. I swear that I will do everything in my power to restore this door.”

“Ah... Thank you...”

No... I can barely process Ande’s words. Not being able to come to this world anymore... That’s just...

...In truth, I know I was lucky. If I had used an even stronger spell when the orc appeared, or if I had hit a more critical part of the barrier magic, the door to the other world might have closed right then and there, and I would have been unable to return.

Moreover, if Ande hadn’t come to the great mage’s house, I wouldn’t have had any knowledge of magic. It’s entirely possible that I wouldn’t have even realized the problem until it was too late to go back. And because Ande is here now, there is still a chance that the door can be maintained.

“...Is there anything I can do?”

“...No, not at the moment.”

...Yeah, I figured. I only inherited my power through the great mage’s succession magic; I don’t have any real knowledge of magic. If a large amount of magic power were needed, that would be one thing, but beyond that, I’m completely useless.

“Got it. Sorry, but I’m counting on you.”

“Ah. It pains me that I cannot simply tell you to leave it to me, but I promise to do everything I can.”

“..................”

After that, Ande explained the current situation based on what he had managed to investigate over the past few days. According to his assessment, the door should remain connected for the next few weeks to a few months. However, there are no guarantees, and it is possible that it could close at any moment.

Whether or not the damaged part of the barrier magic can be repaired is still unknown. And once the door closes, there is no telling whether it will ever be possible to reconnect this world with mine. In the first place, no one knows how many different worlds exist, nor why this one was connected in the first place.

According to the documents left by the great mage, even he did not understand why my world was connected. In the letter he left behind, he wrote that the moment I opened the door from my world, the connection to this world was established—but even that was merely speculation.

“...It’s all too sudden. Then again, I guess I’m just going back to my normal life.”

From the very start, the existence of a door connecting two different worlds was bizarre. If it disappears, then I simply return to my original life.

“Hoo!”

“...Yeah, at the very least, you’ll still be with me, won’t you, Fūsuke?”

Fūsuke is the summoned beast I brought forth. As long as I don’t dismiss the summon, he can stay with me in this world. That requires magic stones, but I’ve been buying them from Gildart for some time now, so I have quite a stockpile. Still, since the door is closing, I should probably gather as many magic stones as I can right now.

“...If the door really does close, what should I do?”

“Hoo...”

“Yeah, you’re right. That’s something I need to think about properly.”

There’s a chance I may never be able to return to the other world. There’s also Sara’s and Lilith’s confessions... And what I can do right now. I need to think this through carefully.