“This has got to be the spot.” No doubt about it Silas was certain this was the dungeon, random holes in the ground do not spew seemingly endless amounts of mana by themselves. It had taken them weeks of wandering around in the woods and sleeping on roots but they were finally done. He was looking forward to sleeping in an actual bed and taking a warm bath when they got back to the city.

“Are you sure sir? It just looks like a normal hole in the ground to me.”

Ah the bane of his existence, he could never understand why Gabriel felt the need to take apprentices every few decades. He personally couldn’t stand the little idiot who had for some reason been sent along with their expedition. Gabriel probably had some stupid idea like, he was gaining experience or some such.

“Well, whatever your name is, even you with your half-blind mana sense should have been able to feel that surge in the ambient mana the other day, yes? Good, and that normal-looking hole in the ground is putting enough mana to attract every animal for miles around. Maybe try looking properly instead of asking stupid questions.”

Silas started fishing around in his bag, the inhibitor was around here somewhere. “Tim.”

“What was that?” What was the apprentice going on about now?

“My name is Tim, we’ve been traveling together for days, you should have remembered by now.” Kira started snickering from the back as she handed over the inhibitor sphere.

“Whatever you say, Jim.” Silas grumpily snatched up the inhibitor which looked like a metal sphere filled with what looked like clockwork parts. He injected a small amount of mana into the contraption and lobbed it at the dungeon entrance still a good fifty feet away. With air magic ensuring that he hit his target, Silas turned around to head back to camp, it was time for a nap.

Seeing the flabbergasted looks of his traveling companions brought him up short. “What? I’m not going anywhere near the entrance of an unexplored dungeon. Who knows what's in there, I didn’t get this old by being stupid, the adventurer’s society meatheads can figure out if it's safe or not.

The massive flow of mana behind them petered off as the mana was redirected into the inhibitor’s runes. The helpful little thing would absorb all the mana coming out of the dungeon to power a concealment spell over the entrance. It wouldn’t be good at all if the dungeon attracted something too powerful for it to handle and got destroyed now would it. The inhibitory wouldn’t last forever as its mana crystals would eventually just burn out under the strain of absorbing that much mana but it would last for about a month which should be plenty of time.

It was still early morning so this should be the perfect time to send the signal back to Corinth. Reaching the clearing they were using as a campsite, Silas stretched his hand up into the air and shot what looked like a tiny spark of fire off into the air. The little spark traveled quite a ways straight up into the air, before exploding violently in a shower of green sparks that could be seen for miles. The spell was mostly just noise and light, but it got the job done, the sentries watching for them would have to be blind and deaf to miss that.

Swish, thunk. “Ouch Kira, what was that for?”

“Warn us next time you do that you idiot, being surprised with a giant explosion this early in the morning is not what most of us call pleasant.” Fair enough. Silas apologized, then settled back against a particularly comfortable tree and closed his eyes. It was going to take at least another week for the adventurer’s society and mage guild reinforcements to make their way here. In the meantime, he would finally be able to catch up on the sleep he had been missing.

Something’s wrong with the entrance.

How can you be sure Valens? You might just have killed off all the surrounding wildlife.

The core huffed in irritation, he still hadn’t gotten the wild cat pattern, and he refused to believe that he had completely depleted the entire forest. There should still be something coming into the dungeon every so often even if it's an insect, but there have been absolutely no intruders for four days already.

Even if you are right and something is wrong with the entrance, there’s nothing to be done about it.

Oh yeah, why don’t you just stroll out of the dungeon and check on things for me?

Silence, Valens made sure to memorize the expression of the proud drake looking like a deer staring down a fireball. So you noticed that, did you.

Yes, I did, and I would also like an explanation of what you did to seal off my dungeon before. Just so you know you're a terrible liar.

I didn’t do it this time I promise. Valens knew that the drake hadn’t been outside of the core room for a long time. So first off bosses can leave the dungeon without dying, that's because their bond to the core is strong enough to survive even outside of the dungeon’s aura. It's generally not a good idea to send you bosses wandering around the countryside though. It leaves very vulnerable to attack and local sentients tend to take issue with the practice.

That seemed sensible enough, the core had no plans on sending away his bosses; they could grow just fine in the dungeon without leaving him exposed. Sora had finally started making progress through tier two, although it was still slow going because of the still minimal amount of tier two creatures he had.

The second thing you asked about are runes, which to be frank I didn’t really want to tell you about yet. They’re extremely dangerous and have a tendency to go disastrously wrong, also I am almost positive that low-level runes and rune sequences will be useless to you as a dungeon.

That’s interesting and all but what exactly do runes do and why would they not be helpful for me?

Magnus takes out a slab of stone from wherever he seems to pull his endless number of goodies. Lifting a claw he delicately cares a swirling shape onto the slab. This is a basic rune for mana which in this state will only store any mana you put into it. Since it's already carved you just need to add mana to power it, try it.

Valens is uncertain where the catch is but he dutifully reaches out with his aura and forces mana into the rune. Pain, like someone, just stuck him with a needle, the rune is glowing filled with his mana but something is wrong. The dungeon is smaller? The rune is working but why is the eleventh floor smaller than it's supposed to be?

That's precisely the problem with dungeons using runes, for some reason it also takes aura for you to activate the rune. This means that each rune that you use will chip away at the maximum size of your floors which is the opposite of what we need for your current setup.

It made sense to Valens even if he was a little disappointed, he needed all the space he could get for the ecosystem to function. Runes might be fun for traps but those would ultimately net him less experience over time than his food chains. I understand why using runes like this is a bad idea but can you explain to me why you said only low-level runes and runes sequences would be useless. If he could figure out how to use runes without having to use his aura, they would be endlessly useful and versatile.

So there are three basic levels of rune usage starting with just the runes themselves. The fire rune will turn mana into heat, the water rune will create moisture, and so on. The basic runes can then be modified in a rune sequence so say a gathering and heat rune would pull out all available heat in a small area. With me so far?

Valens nodded his non-existent head up and down; it made sense so far. Right, so one of the more advanced uses of runes is to make runic arrays. What makes arrays different from sequences is that once they are started they can sustain themselves off ambient mana. This is rather complicated though and not something meant for beginners.

Drawing his mana back out of the rune Valens sighed and relaxed minutely as his aura sprang back to its proper size. So if I’m understanding this right I just have to learn how to make these arrays and then I can play with runes however I want in the dungeon?

You make it sound easy but I’m not even sure you’ll be able to make a single rune period much less an array. Most mages only start trying to mess with runes when they are in tier four and usually don’t make anything useful until tier five. You are a dungeon so your aura should help you with this but it just might be too complicated right now.

We’ll see about that. Valens absorbed the stone with the mana rune on it, he could do this it was just carving a pattern into a rock. Carefully he etched the symbol into the side of the core room. Umm Valens you might not want to… The core heedlessly poured mana into the rune, and the entire thing went off with a boom. Valens was more than a little surprised and stared in shock at a rather sizable piece of stone that was suspended inches away from his core.

Magnus lowered his claw to the ground letting the shard tumbled to the ground and sighed. As I was saying you might want to experiment in another part of the dungeon. You have probably noticed but runes tend to explode if they’re not properly formed. Let me know when you get the hang of the mana rune, you’ll need to learn a few others and then how to link runes before you can manage even the most basic array.

What did I do wrong it looked identical to the one you carved for me?

That is exactly the problem with you trying to make runes this early, I don’t think your aura is strong enough to catch the minute differences that make a successful rune versus one that will blow up in your face. The drake started fiddling around with a ring on one of his right claws that Valens never remembered seeing before. He was going to figure out the arcane symbols eventually, but it would probably be for the best if he moved his testing to a different area.

Now that you know about runes, I can start setting up more robust defenses. The drake now had several objects that looked like stone cylinders that were liberally covered in runic symbols. Magnus began leaving the objects around the room, and Valens watched in fascination as they sank through solid stone. From the mana flows, it looked like the pillars were arrays that interacted with their fellowes to make an even larger array. Shimmering barriers of mana enclosed the entirety of the core room, passing through solid stone like it wasn’t even there, a secondary field also enclosed the core itself.

Seemingly satisfied with the result Magnus settled back down and closed his eyes. Valens tried to make the mana rune three more times, a suitable distance away from the core room of course, but he got sick of regrowing the plants over and over again. You know what I’ve had a long day, I can mess with runes later. The core settled back to simply observe the dungeon, amused by the hundreds of activities going on as his creatures thrived and grew stronger.