Beyond a low embankment—one that could easily be climbed over—a large river came into view. Though “large” might be an overstatement, as it was less than twenty meters wide. The current was gentle, and the water didn’t appear to be particularly deep.

Now, however, the river was white and murky, frothing with bubbles. And within those bubbles, black eels writhed and squirmed.

“…That’s a little disgusting.”

“Yeah.”

“Eels are monsters, but they’re edible, so the fishermen around here usually come to catch them every day. That’s why it’s unusual for them to swarm like this… but right now, it’s a period of abnormal monster outbreaks.”

If they spawned in such large numbers, it should’ve been a bountiful catch—something to celebrate.

So why weren’t the nearby fishermen or adventurers coming to harvest them…?

Mika tilted her head in puzzlement. Seeing this, Gatt picked up a stone from the ground and said,

“Let me try something.”

Then, he casually tossed the stone into the swarm of eels.

The moment the stone landed in the middle of the river, a blue flash erupted.

Zap! Crackle-crackle-crackle!

A fierce sound spread outward from where the stone had fallen.

“Eels can use weak lightning magic. One alone isn’t much of a threat, but…”

Normally, eels hid alone or in pairs between rocks at the bottom of the river. When prey approached, they would paralyze it with an electric shock before biting down with their sharp teeth. That was why fishermen used small traps—ones that could only catch one or two at a time. Even if they got zapped while pulling the trap up, it’d just be a mild tingle.

But with this many swarming together, isolating a single eel was nearly impossible. Trying to cast a net would be pointless—the surface was so crowded it’d be hard to even find a spot to throw it. And if anything was thrown in, the eels would react to the disturbance by releasing electricity. One eel’s shock would trigger a chain reaction, spreading to all the others nearby.

Even now, pale blue sparks continued to crackle sporadically within the white foam.

“Hmm… I guess we can’t just wade in and scoop them up like loaches.”

…Mika, it seemed, had genuinely considered charging in there.

Since most of the day had been spent traveling, the real extermination would have to wait until next time.

As she stared at the squirming black backs of the eels, Mika racked her brain—just how could they catch them?

That evening, after returning home and finishing dinner, Mika decided to consult her husband.

“Hey, how do you think we should catch eels?”

“Huh? Eels this time? I’d love to eat some! Alright, hold on. Let me look it up!”

Her husband cheerfully turned to his computer and searched for various eel-catching methods.

Among them, they decided to prepare the simplest tools they could gather. Then, to ensure they’d be ready for the next extermination trip, Mika packed them into a slightly larger backpack than usual.

The following Tuesday, Mika headed to Warehouse No. 4 with a hiking backpack slung over her shoulder. She had also borrowed several shopping baskets from the store—to hold the captured eels. Of course, there was no way they’d fit all the eels, but she figured it’d be fine to split the task over multiple trips.

After regrouping with the others, they immediately set off for the coastal town. Since they’d left early in the morning, they had plenty of time.

Like Mika, Dada and the others seemed to have put some thought into their approach, bringing various tools of their own.

They spread everything out on the embankment like a picnic.

“Alright, let’s try out some ideas.”

Once again, the Annihilating Poison Mist was off-limits—this was about securing ingredients.

The battle between the eels and Mika’s group had begun.