With no time to deal with the gate that should have been destroyed, we huddled together at the center of the slime’s encirclement and battled the undead.

We struck them dead one after another, but they just kept coming no matter how many we killed. In fact, it felt like there more of them now. I know it’s a fantasy world here, but this is just crazy. An endless zombie mission? Give me a break. We’re somehow holding up thanks to the slimes, but this is still the first time I’ve been pushed to my back by sheer number alone since coming to this world.

...What’s going on outside? The mimic slime should be there...

Linking my senses with the mimic slime battling outside, I found out that the slimes have overwhelmed the undead there. It looks like the undead are only spawning from inside the castle.

While I was relieved to know that the monsters were only spawning inside, some roam weapons in the shapes of hammers or spears came flying at me. I promptly shot them down with light magic, but at this rate, there won’t be an end to this!

“The undead don’t seem to be spawning outside. Shall we retreat for now?” [Ryouma]

“At this rate, we’ll just end up exhausting our strength and magic.” {Shiva]

“Indeed, regrouping with the slimes outside seems to be our best bet.” [Sebasu]

Seeing our anti-air group doing well as they battled the lich in the skies, we opened the gate and went out with the slimes.

Fortunately, the gate didn’t end up having some weird power that kept us from opening it, and we were able to easily open it from inside. I erected a pillar of stone to keep the gate open before we left. We didn’t bother destroying it anymore since it seems it would just get fixed anyway.

The undead chased after us, and though the slime numbers have doubled, the battle seemed like it would still continue. But then when we got far enough, pillars of fire rained from the sky around the castle gate.

“Uuu...”

The wind took with it the heat of the flames as it blew the rising smoke and spread the smell of scorched and rotting flesh. I couldn’t help but frown upon getting a whiff of that, then a voice called out to us.

“Is everyone alright?” [Remiri]

It was Remiri-neesan, who had been battling the lich. Afterwards, Rheinbach-sama flew to where we were as well.

“What happened to the lich?” [Ryouma]

“We couldn’t kill it. It was really tricky, and it managed to run into the building.” [Remiri]

“It wasn’t for naught. It turns out that lich isn’t very strong in a straight up fight. The only thing it’s good at is backstabbing and running away. It can’t use anything other than dark magic too.” [Rheinbach]

Weak in a straight up fight... huh. That’s not something you hear a lot. But if that’s the case, then...

“The adventurers that attacked ahead of us were probably caught.” [Shiva]

As the billowing wind scattered the rising smoke, Shiva-san solemnly looked toward the castle gates. And out of the fire and the smoke did the undead appear, seemingly unperturbed, as if nothing at all had happened.

There’s no way there’s really no end to them, right? They must have a limit.

“This is a problem... Does everyone still have magic to spare?” [Ryouma]

My magic is fine, but I should drink some magic recovery potions just to be safe. The others also drank some before the undead came. As for the slimes... Well, they seem to be alright.

“Now what? At this rate, we’ll take up too much time.” [Remiri]

“My dragons could just cook them all, but we should save the surviving adventurers first.” [Rheinbach]

We might have to abandon them if the situation turns for the worse, but for now, we have to prioritize saving them, as we still haven’t been pushed that badly yet. The undead aren’t strong, but they’re really annoying.

To begin with, just where is all that undead coming............Huh?

After having gotten some distance and seeing the way the undead appeared, it suddenly felt like I’ve seen something similar before... Ahh!

“I’ve got it!” [Ryouma]

“W-What is it all of the sudden?” [Remiri]

That moment of eureka ended up surprising Remiri-neesan, bringing the attention of the other three to me.

“I was wondering why the way the undead appeared felt similar, and I finally realized that it’s because it’s exactly the same with the grave slimes.” [Ryouma]

The other four became thoughtful.

“Now that you mention it, it does seem like it.” [Sebasu]

“And that would also explain where all those undead were hiding, but...” [Remiri]

“Even if there is a magical beast with a similar ability, the question is where?” [Shiva]

“Honestly, I can’t see anything but undead.” [Rheinbach]

It was here that I shared something I thought of.

“But what if that entire fortress is that magical beast?” [Ryouma]

“...The gate we destroyed was fixed after all. And there is precedence for objects turning into magical beasts, like the roam weapons for example.” [Sebasu]

“It just might be then.” [Remiri]

We all looked toward the fortress.

“We can find out for sure if we use ‘Monster Identify’. Remiri, I’m going to approach the fortress. Back me up.” [Rheinbach]

“Gotcha. We’ll come back right away, so you guys just wait here, ok?” [Remiri]

Like that the two rode on the backs of Rheinbach-sama’s dragons and approached the castle. After a few seconds, they came back.

“Ryouma-chan’s right. The fortress is a magical beast.” [Remiri]

Status

Name Ghost House

Skills Spawn Ghosts Lv7; Enshrine Remains Lv9; Mimic Lv9; Regenerate Lv7

After hearing the results of Rheinbach-sama’s Monster Identify, there was no doubting it.

That fortress was definitely the one responsible for all those undead. That Enshrine Remains skill proves it. It’s exactly the same as the grave slime’s.

That Spawn skill of it has also got to be related with the undead, just like the Attract Ghosts and Absorb Ghosts skill are. It says spawn, so I suppose it’s an ability that creates undead? Wait a moment, wouldn’t this mean that this thing might be the reason for the sudden increase of undead in the troll canyon?

I see it has a Regenerate skill. That’s probably what fixed that gate. It’s an ability that the undead also possess, so I checked with the grave slimes whether the fortress was also foodundead, and it gave me a ‘Now that you mention it!’ feeling in response. It looks like they were fooled too.

After that we tried breaking the castle walls, but it just fixed itself again. As for light magic, the ghost house was originally a fortress, so it didn’t work. Although it seems that the undead stopped coming for a moment when the ghost house had to regenerate itself.

Observing the ghost house through the slimes, it seems that when we destroyed a part of the castle walls, those parts stopped being a part of the magical beast for a moment, but only until it regenerated. So the fortress can fix itself and there’s no end to the undead... Isn’t there an easy way to kill this thing? Like a nucleus or something like the slimes?

Also, we’re still investigating, but it seems highly probable that this ghost house doesn’t have any way of attacking aside from spawning undead.

If so, then I wonder if the lich was born from this ghost house? Or perhaps they’re benefiting from each other instead?

In any case, I’m glad I had the grave slimes with me. Not just for their fighting power, but also because we probably wouldn’t have figured out that fortress itself was living if not for them having similar abilities.