Project Necro is an official initiative by Re:Library.

The moment the warships plunged into the fog, the sound of wind vanished.

“What the hell? This ain’t the sea anymore.”

I can understand why Garsche is puzzled. The surface of the water is completely calm, like a mirror—more like a lake than an ocean.

“Veit, there are fish here. Shallow-water fish.”

Reported the mermaids while staying close around the warships.
Visibility inside the fog is poor, and it’s hard to see far ahead.

But if that island octopus b̲a̲s̲t̲a̲r̲d̲ is here, then the reef it’s camouflaging as should be here too.
If we accidentally run aground, it’s over, so I ask the mermaids to stay alert.

“Keep reporting what’s going on underwater! Any reefs?”
“We’re searching separately, but this area is deep…”

It seems the island octopus itself is much smaller than the fog’s overall area.

The fog is thicker than expected, even the neighboring warships look blurred. At this rate, there’s a high chance we’ll be ambushed.
I’m not familiar at all with medieval-level naval warfare, but I do know a bit about modern naval battles.
In that case, we should launch carrier-based units to locate the enemy.

“Centaur unit, deploy. Spread out and begin reconnaissance. Never stop moving during the search. Take mermaids with you to watch the water.”
“Got it! Leave it to us!”

Filnier hoisted her massive two-handed spear and smiled.
Just don’t overdo it…

Two hundred elite centaur soldiers disembarked from the five warships onto the water’s surface one after another and formed up in front of Filnier.
Filnier herself held her large two-handed spear and encouraged them.

“Begin the reconnaissance! Do not engage—prioritize reporting and stealth! The mermaids will watch beneath your feet, so don’t worry!”

The centaur cavalries nodded and silently raised their bows and spears high. That was their reply during a stealth operation.
They spread out to the left and right, then vanished into the fog with light, swift steps.

The reconnaissance probably only took a few minutes, but those of us left behind waited in tense silence.
Our opponent is the “Demonic Sea.” I just hope the centaurs haven’t taken any losses.
Then the centaur soldiers emerged from the fog and returned.
Filnier, at the front, rushed back to just before the flagship and shouted in alarm.

“This is bad—there’s a ship! A ship with sails!”
“What!? What about the reef!?”
“We still haven’t found that! We’re in the middle of searching!”

What does that mean?

In any case, that ship is a clue.
It’s possible the enemy isn’t just the island octopus. We need to confirm—but cautiously.

“Pull the centaur unit back for now! As planned, deploy the decoy!”

This is where Rasie comes in.

“Rasie, I need a sailing ship illusion.”
“Y-yes!”

With a tense expression, Rasie begins concentrating.

“I am the one who deceives the eyes, ears, nose, and fingers. Let my thoughts take form, shaped as I imagine.”

She stretches both hands into the empty air, moving her fingers as if touching something invisible.

Slowly, a ship appears on the surface of the sea ahead. At first it’s blurred, then gradually comes into sharp focus.
A fine three-masted sailing ship. A very common type often seen in Belrüsa’s harbor. Even the crew is properly reproduced. It hardly looks like an illusion.
The crest painted on the mast is a bit too cutesy and feels out of place, but we’ll overlook that for now.

“What’s that?”
“A wolf.”

A wolf, huh.
Right.
I thought it was a dog.

Meanwhile, Garsche looks at the illusionary ship and lets out an impressed grunt.

“Beat me pansy… It don’t look off even to a sailor like me. It’s perfect.”
“It’s not just the part above water that’s perfect. The underwater portion is reproduced perfectly too… or should be.”

That’s why I had Rasie spend days diving into the sea, staring at ship hulls.
Eventually she said, “The bottoms of ships show up in my dreams… Everyone worshiped me as the Saintess, but I got chained to a ship’s hull, and you laughed yor head off while watching, Veit… You did rescue me after that, though.”
What kind of role do I play in her mind?
I’ll ask her someday.

The illusionary sailing ship Rasie created slowly moves ahead of the fleet, at just the speed of a vessel drifting forward on inertia after losing its tailwind.

“You really observed closely, Rasie.”

When I praise her, she smiles shyly while manipulating the illusion with her fingertips.

“Observation and imagination are absolute requirements for an illusionist. You can’t create things you don’t know well, or can’t imagine clearly.”

I see.
She might actually be well suited to being a painter or sculptor.

If the octopus b̲a̲s̲t̲a̲r̲d̲ bites onto this illusionary ship, we can start attacking without taking damage.
Octopuses pursue prey visually. If the illusion is convincing enough, it should fool it.
As I stay alert, thinking that, a lookout shouts.

“Ship sighted ahead!”

That must be the one the centaur unit reported.

“Report the ship! Whose vessel is it!?”

Garsche yells, and the lookout immediately shouts back.

“Th-that’s… the Rainbow Shell, from the Eranya Trading Company!”
“What!? That’s the one that went missing months ago!”

Looks like things are about to get complicated.

Aside from Rasie’s illusion, there’s another ship faintly floating in the fog. It looks completely ordinary. One mast is tilted, so it probably can’t sail properly, but otherwise it’s floating just fine.
Of course, that makes it all the more suspicious.

“A-Admiral! We should go rescue them immediately! If they stay there, they’ll be killed!”

The Belrüsa soldiers are panicking, but I shake my head.
A ship that’s been in the island octopus’s territory this long can’t possibly be safe.

“It’s already too late. Don’t approach carelessly.”

And for a while now, I’ve been faintly sensing a vile magical presence.
There’s definitely something nearby.

“Rasie, bring the illusion closer to that ship. Make it look like it’s coming to rescue them.”

In response to my order, Rasie carefully manipulates the illusion.
Her sailing ship faithfully reproduces the look of moving purely on inertia. Slowly, it approaches the Rainbow Shell…

The next moment, a tentacle bursts out of the sea and coils around the illusion.
A massive tentacle, thicker than a mast, its slick skin covered in countless suckers.
It bends and wraps soundlessly around the illusionary ship.
Of course, it shouldn’t actually be able to wrap around it, but this illusion even reproduces tactile sensation. The tentacle writhes persistently, trying again and again to grab hold.

“Hii! Uwaaah!”

Unaccustomed to seeing octopuses, Rasie lets out an involuntary scream at the grotesque sight.
If her mental state deteriorates any further, the illusion will vanish.

I steady Rasie by the shoulder and urge her on.

“Get a grip. That’s just what octopuses look like. It’s creepy, but it’s just an oversized seafood.”
“B-but that thing…”
“Trust me! Maintain the illusion. With your power, you can protect everyone!”

At my persuasion, the half-panicked Rasie snaps back to her senses.

“Y-yes! I’ll do my best!”
“I’ll protect you. Focus on the spell and don’t worry.”

Rasie isn’t the only one afraid. Human sailors and demon warriors alike can’t hide their fear.
If we hesitate here, we lose. I issue the attack orders immediately.

“Centaur unit, move out! Work with the mermaids to find its main body—the reef! It has to be nearby! Prepare signal flares, and order the armed merchant ships to advance!”

Night-use signal flares are launched at once, glowing faintly through the fog.
I don’t know if the armed merchant ships have seen it, but they should charge in using that light as a marker.
Just in case, I should send a few centaurs as messengers too.

The tentacles attacking the illusionary ship increase to three. Because it’s obsessively targeting the illusion, the centaur unit remains safe.
The octopus b̲a̲s̲t̲a̲r̲d̲ should still have five tentacles underwater. Those could attack the centaurs.
But right now, letting our ships be attacked would be the worst outcome.
Still, what is that Belrüsa merchant ship?

All the tentacles are relentlessly attacking the illusionary ship. Meanwhile, that merchant vessel hasn’t been attacked at all. It’s almost as if it’s waiting for us to approach.
At that moment, I realized a possibility.

“Mermaids on standby, take a look beneath that ship! But don’t get too close!”

Right after that, I knew my guess was correct.

There’s a huge hole in the bottom of that ship. It seems it already fell victim to the island octopus.
Normally it would have sunk, but a massive tentacle was stuck to the hull from below, propping the ship up.
That island octopus b̲a̲s̲t̲a̲r̲d̲ learned that if it keeps a ship afloat after finishing eating it, new ships will come closer.
Using its brain, huh.

Now that we’ve confirmed the positions of four tentacles, I prepare the catapult and wait for the armed merchant ships to enter.
Before long, the armed merchant ships charge in one after another.
In this windless, currentless sea, sailing ships can no longer escape. If we abandon the subjugation and retreat, we’ll have to transfer the crews onto the warships.
Little by little, the situation moves toward a point of no return.
Even I’m starting to feel tense.

According to Marlene’s notes, the island octopus’s tentacles lifted ships. But judging from how they’re moving now, they don’t seem to have that much strength.
They are, however, just the right thickness to entangle human-sized prey. If you get dragged in by one of those, there’s no way out.

At that moment, the centaur unit returns from the fog.
Filnier, running at the front, shouts at the top of her lungs.

“Senior, we found the reef! It’s further in!”
“Good work, Filnier!”
“But be careful! Multiple tentacles are guarding the reef! We lost two!”
“We’ll avenge them! Centaur unit, fall back for now!”

For octopuses, tentacles are also organs for swimming, using the membranes between them.
As long as it’s using all its legs for combat, it won’t be able to flee anywhere.

“Warships, tow the sailing vessels! Dragonfire engineer unit, prepare catapult fire! Load the first shot!”