Now I’m no murderer, or at least I really don’t want to be one. These traps are lethal, and that’s obviously intentional.

So, you might ask, “why would I murder trespassers, isn’t that overkill?”

And you’d be right, it definitely is overkill. But here’s the thing, they’re not trespassers.

They’re malicious surgeons.

...I know, I know, but hear me out. A trespasser is someone who enters a property uninvited. Bad, yes, but not justification for murder, not even close.

An example of a malicious surgeon would be someone who subdues you and proceeds to steal your kidneys without permission. Worse yet; your heart.

If someone wants to steal your heart, is it ok to use lethal force to defend yourself? Eh, it’s certainly questionable, but right now I’m leaning towards ‘yes.’

You see, my dungeon is not my property, it is my body. This is one of those things that only really makes sense to a dungeon core. Of course, the case isn’t so clear-cut; in my situation the line between the two is very fuzzy. What’s important is intent. If a human stumbles in to harvest fire flowers? I’d certainly try to expel them but I most definitely wouldn’t kill him. Furthermore I’d heap on copious warnings pertaining to traps they may be about to unwittingly trigger. Worst case scenario? They ignore my pleas.

But I already know those tribal cave people seek to take my core. That will not stand. Sure, I might tolerate a scouting party, as long as they don’t penetrate too deep into my domain. But if they come along and start blasting everything or show signs of being extremely powerful, I might panic. Again.

Long story short, I hope I never need to use my traps. I’m just preparing for the worst.

Or at least what I know to be the worst, who knows what other dangers this world of impossibilities might harbor? How do you even begin to prepare for the unknown?

Before I begin construction on the pitfall traps doubling as ambush sites, I want to solidify the design of some crushing traps.

One of the myriad benefits of dungeon core neurology is a perfect memory. In particular, one useful ability emerges; I’m able to visualize designs in my head and alter them in any way I see fit, at any time. With my imagination being the only limit. This is good because it means I’ve no need for written blueprints or notes.

For now, I intend to simply repurpose my soulstone crusher’s trigger for my latest traps. That is why I’ve decided to do it before constructing the pitfall traps, it probably won’t take any longer than an hour, and I want to build both types of trap simultaneously.

…

I was right about the trigger’s design being easy to repurpose, however, I encountered some other setbacks.

It’s easy to say “I’m going to make a trap which makes a tunnel collapse.” But how do you actually do that without sacrificing its structural integrity?

The answer is; you can’t. Or at least you can’t easily.

An interesting feature of the local geology is that the surrounding rhyolite bedrock is suspiciously unjointed. In other words; solid rock is usually riddled with fissures that prevent it from being a truly continuous solid.

One of the greatest challenges of boring tunnels through rocky bodies, let’s say Earth, is that the crust is not a coherent whole. The substrate is ‘jointed.’ When boring a tunnel, the rock needs to be shored with long screws called ‘rock bolts.’ Rock bolts are drilled into the stone face to anchor unstable rock exteriors (the tunnel’s edges) to the secure interior of the stone. Depending on how fragmented the nearby crust is, these bolts can be anywhere from two to four meters long.

Earlier, I observed how fortunate it is that the crust around me is so unnaturally uniform, thus rock bolting hasn’t been necessary. Still, I’ve kept a lookout for substrate joints in order to avoid any catastrophes.

Now though, that boon is working against me. When digging a tunnel, joints of crust which were previously held in place by other joints beneath them, may find themselves unsupported when those supports are removed. Rock bolts penetrate through an entire joint and pierce more distant ones, thus anchoring the loose joint.

If my surroundings were sufficiently jointed, such massive cavities as the forested cavern and the canyon would’ve been substantially more impossible than they already are.

Don’t get me wrong though, they still have no right to exist, regardless of rock jointing.

Because the crust is a coherent solid here, I have no choice but to add artificial fractures to destabilize my trap corridors.

This isn’t too difficult on paper, all I have to do is make some well-placed cuts. In practice, though, it’s not so simple.

If I’m not careful, I could trigger an unintentional collapse. Furthermore, if I destabilize the wrong regions, I may be unable to contain the effect. That is to say, I may accidentally affect other nearby locations in my dungeon. And if a fluke domino-like chain reaction occurs, it may even be noticeable from the surface.

I’d like to avoid forming a sinkhole in the middle of Sevit.

In order to confine the aftermath of the cave-in traps to a manageable area, I’ll only implement them on a small scale in narrow passages.

As for how they’ll work, consider an arch fashioned from stone blocks. Without a keystone at the apex, the whole thing crumbles. I will fracture the stone walls and ceilings of tunnels with fissures spaced in an orderly fashion to allow them to collapse inwards when the top central keystone joint is released.

The ‘keystone’ rock joint will run down the center of a tunnel and hold the walls and ceiling in place. It will be secured to the bedrock above with makeshift rock bolts which will be formed from the trunks of my widest fungiwood specimens, which have a thickness of three-quarters of a meter. As I’m currently unable to work with metal, this will have to do for now.

The top of the trunk embedded in the solid rock above the fractured portions of the trapped tunnel will pierce a hollow cavity with access to the rest of my tunnel network.

Originally I thought I’d apply a similar mechanism to the soulstone crusher; a lever. Unfortunately, I now see that the trunk will experience a load much too strong for such an apparatus. What I have in mind now is much simpler and robust, but has the drawback of being more difficult to trigger.

The top of the trunk poking into the hollow cavity will have a hole bored through it perpendicular to its length. Through the hole, I will insert another shaft to act as a securing pin which will prevent the fungiwood rock bolt from slipping downwards and thus dislodging the keystone and initiating a collapse.

Imagine a ‘T’ or a cross; the vertical portion is the trunk holding the keystone to the tunnel’s true ceiling while the horizontal portion is the shaft preventing it from falling down the vertical shaft due to the keystone’s weight. When the horizontal pin is pulled out, the trunk is free to slip away.

As the pin serves as the interference preventing the trunk from falling, it will be difficult to remove. Yes, I should have no trouble using a tethered rope as always, but the biological triggering option will be harder. Nothing less than one, or more likely two, super helpers will be required to dislodge the firm pin, so I’ll have to make sure I never commit all of them in a defense lest I run out of operators.

Now that I have mental blueprints prepared for a few varieties of pitfall and cave-in traps, I’ll set to work constructing the initial batch right away. For now, I’ll focus on building a few dozen each, and after that I’ll slow down to give me time to work on other priorities. Additionally, I’ll use my recently improved multitasking skills to modify a new species simultaneously…

…

I’m not sure if I’ve ever worked so hard in my life, but then again my life has never really been on the line until now. Who knows, maybe dungeon cores just have a naturally high work-ethic? For one week I’ve been filling my dungeon with lethal traps and inventing a new species to aid in my defense.

I’ve made sure to evenly space traps throughout my dungeon such that no invaders will be able to pinpoint the location of my core based on the level of lethality. Furthermore, I built additional airlock doors on dead ends to serve as decoys. Imagine wasting mana trying to blast through a door which leads nowhere, hilarious!

I also implanted a compulsion in every animal large enough to trigger a pitfall trap to avoid them. I’ll get my regular leafcutter ants to prevent any especially heavy plants from taking root there as well.

Mr. Normal has decided to make his presence known by announcing his theft of my hard-thought species name.

While I was booby-trapping my home, I also created this new species of fungiwood tree. The progress was unusually slow because my mana capacity has not been topped off ever since I anchored my domain to the soulstone.

I’m quite proud of this idea; firestarter tower-caps have been modified to grow gap-filled perforated trunks. Similar to a bird’s bones, the wood is filled with extensive hollow galleries that serve to drastically decrease the fungiwood’s density.

The reduction is nothing to shake a stick at, either. Firestarter fungiwood is three times lighter per unit volume than its wild progenitors.

Thanks to the absurdly fast rate of growth in my dungeon paired with my efforts to cultivate them in the richest soil available, I’ve had the opportunity to cultivate some firestarter tower-cap saplings and begin testing their material properties. Regrettably, my results have been poor. While lightweight, this new variant of fungiwood is disproportionately weak as a structural material.

That’s fine though, as you’ve no doubt already inferred from my name for them, these mushroids will serve another purpose; thanks to the fungiwood’s airy nature, even while alive it is easily ignited and burns exceptionally fast.

I wish to plant thick groves in strategic locations around my dungeon. During an invasion, I will use a fire spell to ignite stands of firestarter tower-caps near enemies. Used in conjunction with my airlock doors, I can either asphyxiate or control the movement of aggressive forces by smoking them out.

Depending on how many firestarters I plant, this could become quite the deterrent. In a few short months, I should have more than enough to deal with even the strongest offensives.

Whew, let me tell you, these changes have been refreshing! I feel much safer now that I’ve heavily invested in my own security. Of all my precautions, creating an escape route for my core is the most reassuring. That said, I will be pained to abandon all of my hard work here if such a thing ever becomes necessary.

Perhaps there are other last-ditch methods to deal with invaders that don’t involve running away?

I considered restructuring parts of my dungeon to facilitate very large-scale cave-ins, however, by doing so I would run the risk of unintentionally causing a premature collapse.

But this is still an interesting line of thought; sacrificing something in my dungeon will always be preferred to losing in entirely.

Which gives me an idea.

By Sevit flows a very large river fed from somewhere beyond the cataclysmic volcano. In an emergency, I could tap into it to flood my entire domain and thus flush out any hostile entities. Of course, doing so could irreparably damage the ecosystems I’ve worked so hard on, but it’s still preferable to losing everything.

And the best part is, it wouldn’t even be hard at all! In fact, I can go ahead and prepare a duct to carry the water here for whenever I need to breach the riverbed.

Better yet, I can go ahead and breach it! As long as I’m careful, I should have no trouble choking the flow and will be able to drain the output into the cave network far beneath me. Then whenever I’m in a tight pickle, I will simply block the outlet which should flood the rest of my dungeon under a great deluge!

Underground flash-flooding is no laughing matter, after all.

There are also many useful things I can do with flowing water.

First, I may eventually be able to harness it for mechanical applications. When I decide to commit to the ladder of increasing precision which will allow me to work metals, I will need to start somewhere. The hydromechanical lathe is one of the first important rungs.

As it stands, there’s not a whole lot I can do to further raise the biomass of my dungeon. (And by extension, the number of defenders.) I have well-supplied breeding warrens for goliath² beetles, archer pods, cave centipedes, and most especially, dungeon and super helpers. Right now, though, I only have around twenty griffinflies. The primary limiting factor in their population capacity is suitable water features.

Griffinfly nymphs, or “snatchers,” as the locals know them, are aquatic predators who lie in wait for prey to pass them by. Once it does, they launch their extendable jaws away from their bodies with explosive speed. Unlike their more familiar and much smaller dragonfly nymph counterparts, snatchers also hunt for terrestrial prey. They wait just beneath the water’s surface at the edge of the central pond in order to ambush animals coming to get a drink. In a manner almost exactly like a crocodile, they, well, snatch their victims and drag them into the water where they are mercilessly drowned and consumed.

I’ve managed to get the most out of that pond by encouraging the snatchers to not cannibalize each other as well as by providing a steady stream of prey such as cave tortoises, snakes, rodents, and other such animals. Still, there’s only so much that small area can support. I don’t want to go overboard lest the water become too depleted of oxygen and thus stifle the growth of, and perhaps even kill, the colorful varieties of arcanasynthetic corals.

I don’t want those polyps to go locally extinct before I even have the opportunity to do something useful with them!