Grover was kind enough to give us each a bag of holding, so I wasn't trying to carry the eighteen ingots I'd earned over the previous six hours. Thankfully, it had turned out that rank four did not grant such ridiculous strength that he could jog along with the guild master while carrying the weight of three thousand ingots, and that these bags effectively cut the weight of their contents by ninety percent. Of course, that still meant he was jogging while carrying the weight of three hundred ingots, which was only marginally less ridiculous.

Mythril was a lot lighter than silver or steel. I hadn't really noticed with my rings, which were light anyway, but it was certainly obvious now. I guess it was an alloy of silver and mana, and mana didn't weigh anything, so that made some sense, as long as I ignored the fact that the ingots didn't expand during the conversion, and the extra mass just disappeared somewhere. I'm pretty sure mass wasn't supposed to vanish like that, or if it did, it should be converted to energy and cause an explosion big enough to blow up the planet. Unlike mythril, mana infused steel was no lighter than regular steel, because who needs consistency? Trying to apply any physical laws in the face of mana would be enough to drive anyone crazy.

We entered the tenth floor boss room, and Kari and Isla alike opened their eyes wide in shock. Obviously Isla had never been this far. Even Grover looked surprised. Then the guild master did his thing, and the army went away. I'd thought Kari had looked shocked before, but that display broke her, and she just stood there wobbling. I gave her a friendly tap. "And to think he complained when I called him a beast."

"What are you talking about, you brat? This is only floor ten. Just you wait till you're on floor fifty, where a monster can do that much damage by snorting."

The guild master huffed and stormed off towards the teleporter, but Grover stopped him. "Isn't there supposed to be another hidden room here?"

I looked over towards the back of the room, where the door stood open. I wasn't sure whether I should encourage this or not... "There is, but there's not much in there unless you like art galleries."

The guild master huffed again. "And don't forget the mysterious voice. I don't want to prod whatever telepathic monster that was, particularly after doing this much damage to the dungeon."

I looked around the room, which had already half repaired itself, the damaged floor wriggling and regrowing like it was alive. "I don't think you did anything permanent."

Grover shook his head, beard swishing like a pendulum. "I'm more interested in the way it's hidden."

"Soul magic."

"So I've heard, but you didn't mention any monsters around here, which means an enchantment. I'd like to see that for myself."

Were soul magic enchantments not a thing? Yes, they must be, because my [Basic Runecrafting] had given me recipes for mental stat boosters... Speaking of which, I don't mind abandoning the money, but I didn't want to ignore the magic item. But what to do with this overzealous enchanter? "How do you intend to see it for yourself when it's completely hidden from you?"

"Maybe it'll be visible from the other side? It's worth trying."

I looked over to the guild master. "Up to you, but last time the teleporter vanished as soon as we poked it, so I suggest anyone not interested evacuates now."

The guild master snorted. "Nope, I'm out of here. You and Grover can poke it on your own if you're that desperate."

Grover whopped the guild master over the head, which seemed like a brave move given what he'd just done to the room. "Where's your sense of adventure gone? You've spent far too long sat behind a..."

The world went white, and as my eyes adjusted, I could make out the goblin statues and surrounding wall of the surface.

"...desk. What in the blazes?"

Something went clink on the floor in front of me.

Amulet of Earth Protection (Rank 2)

Well, that was nice; I hadn't even opened the chest. Not something I needed right now, though. "The dungeon just spat out an amulet of earth protection, if anyone wants it."

"Wait, what just happened?"

"We got kicked out of the dungeon. That was exactly the same as when we were removed from the secret room last time."

Grover muttered. He seemed rather less chipper than I'd assume a dwarf should be after getting their hands on a few hundred bars of mythril. He must have really wanted to work out that enchantment. I imagine that Erryn didn't want him to work out that enchantment, or else she wouldn't bother with using it in the first place. I didn't see any runes down there, but I wasn't exactly looking. Maybe they were really small?

Isla, having froze up for a while, finally returned to reality. Her take on the whole thing seemed to be that since it was way above her level and she didn't understand any of it, it would be best to ignore it. "Umm... I'd quite like that amulet if no-one else wants it."

I tossed it over; there were no objections from me. Kari just stood there shaking her head. "I was never interested in dungeons, and I see now that I made the right choice... Well, nice meeting everyone, but I need to head off home before it gets too late."

Grover didn't seem to have given up. "Well, we'll just have to get in there tomorrow, before we get..."

His face went blank, as did Isla and the guild master. Even Kari stopped walking, standing still not far from the gates to the city. Then everyone resumed, and Kari kept walking as if nothing had happened. Isla was the first to speak. "I should head off too. Do you still want me tomorrow? I gained a skill level today, but I still can't make mythril."

Can't she? She's only one level behind where I was when I first made it. Apparently I was right at the edge...

Grover answered her, now sounding far happier. "Yes, please. Converting the steel is useful too."

It wasn't just the skill level; she'd gained a class level. So had Kari, for that matter. The day's work had been well rewarded for them both. But that suddenly seemed less important; I'd bet my stash of mythril that Erryn just did something to everyone's heads, and I'm not sure how to feel about that. Why was I spared? What did she even just do? And why did I feel worse about that than things like the dungeon core? It shouldn't make any difference if messing with their memories was pre-planned or not. I addressed the guild master. "What's the last thing you remember before we left the dungeon?"

"Huh? You fell asleep or something? I slaughtered the goblins, we left the dungeon. That's it."

"Did I loot the chest?"

"What, of course you didn't. We... Huh? I suppose you must have done... When? Well, that's a neat trick. I didn't even see you."

I could see his face settling as he noticed and then explained away the inconsistencies in his memory. Looks like all the talk of the other door and subsequent forced teleport had been edited out. They've probably forgotten the door even exists. How do I phrase a question about it that doesn't make me sound insane? Oh, never mind, the guild master has walked off without even saying goodbye. I'll just wait till tomorrow and see if anyone mentions it.

Isla was politer, waving then turning around to leave too. That left me alone with Grover. "Thanks a lot, kid. With a supply of mythril, we'll finally be able to put proper enchanted goods on the market."

Hmm? He just said something interesting. "Why does mythril let you sell enchanted goods?"

"Little known fact, but it's the only material that can hold an enchantment indefinitely. People don't want to buy things that are going to break down after a couple of weeks."

"Hah. I was right then. I assumed that was the case, because items from dungeons have their runes inscribed into tiny mythril plates, and I've never heard of them degrading."

"Oh, you noticed that? You have good eyes, kid. We've tried breaking them down and extracting the mythril before, but it always ends up contaminated."

"Actually, a smith friend of mine identified it for me, so don't go praising my eyes."

"Bet it was your idea, though. Makes you wonder what other obvious facts we're completely missing. If your previous world had mana, perhaps there would be a bunch more you could have pointed out."

Perhaps there was. That came back to the whole 'can I do magic without the System' question. I still practised sensing mana without skills from time to time, and not only was I better at it than when I started, but I was still noticeably improving. I would say I was on par with a mid-levelled [Mana Sense]. But when it came to controlling mana, or casting spells, I couldn't do a thing. It was possible it was easy, and I just didn't know how. If it was something I'd had experience with back on Earth, just how overpowered might I have been here?

Waving my goodbyes to the dwarf, I headed back to my dorm for the evening. I had more experimenting to do. It was time I lived up to my [Researcher] trait; I was going to science the System to death and turn myself into a proper overpowered isekai protagonist. First up; could I manually refill my mana pool?

I sat on my bed, eyes closed, cycling my rank one spells until my pool was half drained, then I tried to manually move ambient mana into my body. It did not go well; as soon as I put pressure on the mana, a painful burning sensation blossomed in my chest, like a burst of heartburn. I immediately stopped, but the pain remained, and I noted with alarm that I was down a few points of health. Okay, so that was less than successful...

What happened? I wasn't trying to move much mana at all. Probably not even enough to be noticeable against the natural regeneration rate. Surely I wasn't trying to force in too much? Was it some System thing to force people to use natural regeneration? But Erryn's normal modus operandi would be a soul magic filter to stop anyone even trying it. Something left over from the System before Erryn then? I wasn't convinced; it was more likely I did something wrong.

How, exactly, did I absorb mana naturally? Maybe there was some detail that my perception wasn't sufficiently fine to see. The ambient mana moving into my mystery organ wasn't uniform; it seemed to be forming discrete streams. Maybe there were inlets of some form, and I'd just done the equivalent of trying to force blood into my heart through the wall instead of the veins. Thank goodness I'd only pushed lightly...

Time for more science. If I shift mana through myself, maybe I can do some sort of mana x-ray. If I could work out what shape this organ is, I'd have a better chance of this working. Or I could go and find a human corpse to dissect... Or maybe ask? Healing was mostly cast [Heal], regenerate mana, repeat, but Richard did know some anatomy. Actually, that was a good point; I remember being surprised that everyone here knew what a brain was for, and then poking further and finding out that the purposes of internal organs were common knowledge. Yet no-one had ever mentioned an extra organ. Was that because I'd been leading the conversations with the organs I knew, or was this not a physical bit of my body at all?

Some experimentation revealed a vertically oriented ovoid, with protrusions that were mostly aligned with the mana veins I could see. A few of the protrusions were not, and they seemed to be paired with the streams of ambient mana. Maybe they were what I was looking for. I could afford a few more points of health, so I prepared for another attempt. This time there was no burning, and as I sustained it, I watched my mana tick up slightly faster than usual. It wasn't at a level that I'd even have noticed without the extra precision from [Mana Finesse], but I was pretty sure it was working. I pushed harder, and my regeneration increased further. Then I pushed as hard as I could, and my regeneration jumped by more than half. Not as good as [Meditation], but what if I did this in a dungeon?

ding
Skill [Mana Perception] advanced to level 8
Skill [Greater Mana Control] advanced to level 9
For your research into the nature of mana, [Researcher] awards 2 soul points.
For performing a class related feat, you gain 1 soul point
Class [Body Mage] advanced to level 11