Project Necro is an official initiative by Re:Library.

Several days passed, and the information I needed finally began to come together.

“This is… from Bernehainen…”
“Got it. Let me read it for now.”

I hurriedly took the documents that Seisches of the centaur unit had brought.

This world is full of various monsters and strange phenomena, most of which remain unknown and unexplained.
That said, humans leave records. If they are attacked even once, they try to record it and pass it down to later generations.
The ancient southern city of Bernehainen possesses a vast collection of books. Among them should be records from the age of settlement.
With that in mind, I asked my senior, Marlene, to look through the Royal Library’s holdings.
In my previous life, you could just ask on social media and someone would tell you right away, but things don’t work that way in this world.

“All right. Got a hit.”

There was exactly one monster that matched the search results.
About two hundred years ago, settlers heading for Miraldia encountered a monster while crossing the Southern Calm Sea.
A monster that would attack both ships and merfolk. Stilled wind, stilled tides, and fog.
It matched Parker’s testimony perfectly.

“…An island octopus.”

As the name suggests, it is a gigantic octopus the size of an island. The name sounds oddly humorous, but it is said to be the strongest and most dreadful monster of the “Demonic Sea.”

The documents listed other possibilities, but none matched the conditions.
Flying monsters would be spotted immediately, and if they were capable of attacking merfolk, it would be easier for them to attack humans instead.
There were also undead such as ghost ships, a common sailor’s tale, but if that were the case, Parker the necromancer would have noticed when he encountered it.
Besides, naturally occurring undead in this world generally only attack their own kind.
The merfolk feared human ghosts, but the lack of actual harm was likely because they were of different races.

As for human pirates, unless they are exceptionally vicious, they do not sink ships. Like bandits who prey on trade routes, killing their targets would only cause trouble later.
Apparently Garsche’s ancestors were pirates as well, and even back then there was a “five percent rule” in the Southern Calm Sea.
Five percent—an industry self-regulation rule among pirates that limited them to taking only five percent of the cargo.
With losses at that level, merchants could make up the difference by selling the remaining cargo at a higher price. Trade would remain viable, and shipping routes would not be cut off.
If pirates got too greedy, however, merchant ships would arm themselves in earnest or punitive fleets would be organized, and nothing good would come of it.
So it probably wasn’t human pirates either.
That left the island octopus as the most likely culprit.

When I brought the information on the island octopus to the governor’s mansion in Belrüsa, Garsche immediately clutched his head.

“You’ve gotta be kidding me. Something like this is in our sea?”

Since the documents Seisches brought were copies of books, the only illustration was an octopus drawing apparently done by Marlene herself. Perhaps because of the artist, it looked oddly cute.
But there was nothing cute about the size of the island octopus.
A three-masted sailing ship was shown wrapped up tightly in its tentacles.
Below the illustration, in Marlene’s handwriting, were the words:

‘The Demonic Sea That Attacked the Immigrant Ship Storm Petrel.’

Garsche and his subordinates groaned as they exchanged words.

“Come to think of it, I’ve heard something like that. The first boss said a companion ship sank after they were attacked by some huge monster on the way to Belrüsa.”
“So that wasn’t just one of his tall tales…?”
“Hey, what do you think of my ancestors, huh?”
“But boss, you blow tall tales all the time too.”

It seemed the story had survived in legend as well.
Whether it was the same octopus that Garsche’s ancestors encountered was unclear, but the culprit was practically confirmed.

Apparently Master had also researched the “Demonic Sea” at the library, and her notes contained various detailed descriptions.
True to its name, the island octopus resembles an octopus, but it also appears to be related to shellfish. On the top of its head—or rather, its body—it bears a rock-like shell, which it uses to camouflage itself as a reef.
Small fish gather around reefs, and larger fish and beasts come to prey on them. It is thought that the island octopus feeds on those predators.
A rather cunning type, it seems.
As for why the wind and tides stop, it has not been explained, but Master speculated that it might possess some kind of magical power. Just as werewolves can transform instantly, monsters are endowed with mysterious abilities.
Regarding the fog, Master hypothesized that it might be spraying seawater, like a whale’s blowhole.

Come to think of it, merfolk also live around reefs. Their former home was probably a reef as well. They were the right size to fall prey to the Demonic Sea.
However, the act of “attacking ships” was not mentioned in Master’s notes.
If it tried to make sailors its staple food, ships are large and encounters would be rare. Considering the island octopus’s ecology, it makes more sense that it normally eats large fish.
That was the gist of it.

Rasie, peering over the notes, tilted her head.

“So in the end, is this really the one that attacked the ships?”
“Garsche’s ancestors were attacked, apparently, so it probably does attack the ships.”

Master’s notes were written as biological analysis, while Marlene’s notes were written as historical records.
After thinking for a moment, I reached a conclusion.

“Ordinarily, island octopuses probably don’t attack ships. But the one in the Southern Calm Sea started attacking ships. If you think of it that way, there’s no contradiction.”

Back when settlers flooded into southern Miraldia, suppose a ship accidentally ran aground on the island octopus’s ‘reef.’
From the island octopus’s perspective, that hit would be a nuisance—but also a windfall. Humans who fell into the sea move more slowly than fish and are easy to catch.
If it could eat dozens at a time, it wouldn’t need to eat again for quite a while. Unlike warm-blooded animals, its metabolism should be low.
And once the island octopus was full, it would think:

“Wonder if they’ll come again…”

Of course, that was all speculation, but if it was true, there were plenty of ways to deal with it.
Let’s gather everyone and think up an extermination plan.
That’s what I thought—but for some reason, everyone present was wrapped in a heavy mood.

“The Demonic Sea, huh… that’s a completely insane monster.”

As Garsche groaned, Rasie muttered dejectedly.

“Even the Demon Lord’s Army or the Miraldia Alliance Army couldn’t deal with something like that, right…?”

The members of the werewolf unit wore similar expressions.

“Not something you can handle with fangs and claws…”
“This one’s a bit much…”

The Garne Brothers and Monsa frowned deeply.
Everyone was far more timid than I expected.

It couldn’t be helped. While quickly organizing a subjugation plan in my head, I spoke to them.

“It’s just a monster, isn’t it? Let’s take care of it quickly and put an end to the troubles of the merfolk and Belrüsa.”

The group fell silent and stared at me in surprise.
Uh… sorry about the tone-deaf comment.
Parker asked, puzzled.

“You’re the only one who doesn’t seem afraid of the Demonic Sea at all. That thing sinks large ships, you know?”
“It’s weaker than a Hero.”

The strength of the Aerschis the Hero transcended common sense in this world. I had fought many opponents, but the only one who truly made me think I was done for was him.

Compared to that, this was just an octopus. Chop it up and turn it into takoyaki filling. With Belrüsa’s naval power, the demon race’s forces, and magic, we could manage something.

“The Demon Lord’s Army defeated a Hero. And this octopus b̲a̲s̲t̲a̲r̲d̲ is definitely weaker than a Hero. That means we can beat it too. So let’s get started.”

Everyone looked blank for a moment, then after a while the werewolves nodded.

“Y-yeah… if the captain says so, let’s try it.”
“He’s the man who bit a Hero to death, after all…”

That’s more like it. The werewolf unit’s best trait is its energy.

Garsche, however, was cautious, as befit a governor.

“Hey. You think we have a chance of winning?”
“It’s not certain, but I do have a plan. I’ve prepared strategies for if it really is an island octopus, and for if it isn’t. That said, we don’t have any ships. Lend us Belrüsa’s.”

Garsche crossed his arms and groaned.

“Ships, huh… Actually, we’ve been secretly building new warships without Senate approval, in preparation for a fight with the Demon Lord’s Army.”
“Then let us use those.”

In this world, warships were probably galleys—large vessels rowed by many people.

Garsche gave a troubled smile.

“They were built in secret to fight you lot from the Demon Lord’s Army, you know… fine. We probably won’t be using them for that anymore anyway. I’ll lend them to you along with the old ones. Just make sure you bring them back.”
“I can’t guarantee anything, but it should be fine. And lend us a few merchant ships as well.”
“You’re a greedy one. What do you need merchant ships for?”
“They might be able to carry weapons developed by the Demon Lord’s Army, so I’d like to borrow some just in case.”

Merchant ships are basically sailing ships, but they can carry more cargo.

Garsche looked exasperated for a while, then burst out laughing.

“Fine by me. As long as the shipping lanes are secured, warships and merchant ships are cheap! Go ahead—use them however you like!”

That was generous. Warships cost far more than merchant or fishing vessels, so it had to be a major expense.

“…Though I’d really appreciate it if you could at least return the warships intact.”

It seemed he still had some lingering attachment.

Based on Master’s notes, I drafted a plan to subjugate the “Demonic Sea,” but it would require additional personnel and specialized equipment.

“Contact Tübahn’s arsenal and the crossbow unit of Lüenheit. And, Rasie, you’re going into special training.”
“Me!?”
“Your illusions are the key to victory. I’m going to train you hard until the day comes.”
“Nooo…”

This is all to return the warships without damage.
Do your best.