Chapter 21

Lambert stood at the entrance of the classroom, took a deep breath, and firmly held the letter containing the secret that his mother had given him.

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As cherry blossoms danced in the wind, Misaki opened the old diary and read the words of promise written there.

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Lambert stood at the entrance of the classroom, took a deep breath, and firmly held the letter containing the secret that his mother had given him.

---

Lambert stood at the entrance of the classroom, took a deep breath, and firmly held the letter containing the secret that his mother had given him.

---

Lambert stood at the entrance of the classroom, took a deep breath, and firmly held the letter containing the secret that his mother had given him.

---

Lambert stood at the entrance of the classroom, took a deep breath, and firmly held the letter containing the secret that his mother had given him.

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"Old man Lambert, he's walking so fast..."

"...Even with that heavy armor on."

When Lloyd grumbled, Lily also slumped her shoulders in dejection.

Lily turned her upper body to look back and glared at the rear, wiping the sweat from her forehead with the sleeve of her long robe.

Fiona and her party were desperately running after Lambert, who had disappeared into the third floor.

However, in the third floor, the most powerful monsters were orcs, and they weren't even that numerous.

There were almost no monsters that could stop Lambert, and he was steadily moving forward, leaving Fiona and her party behind.

"Lily, how about those who are chasing us?"

"They seem to be distracted by the monsters. But they're systematically blocking the rear paths. There are quite a few of them, and some might have better perception than me. They don't seem like ordinary thieves. Maybe they're from a secret guild..."

"It seems difficult to shake them off and escape. For now, we can only follow the path Lambert took..."

The bodies of monsters that had been violently slain were left behind, making it easy to follow Lambert.

Occasionally, they encountered monsters eating the corpses of other monsters, but these monsters only gave them a wary glance from a distance and remained focused on the corpses, not attacking Fiona and her party.

Fiona and her party ran through the third floor and stopped in front of a large door that was left wide open. Peering inside, their faces turned pale.

Beyond the door was a large staircase leading to even deeper underground.

"Hey, you've got to be kidding me..."

Lloyd's face contorted.

The fourth underground floor was guarded by a "monster that changes shape like a black shadow," and since the discovery of the Ainzas underground labyrinth, no adventurer had ever managed to overcome it.

It was a place where second-rate adventurers like Lloyd and his party had no business entering.

Lambert wasn't entirely without teamwork.

While his actions sometimes seemed eccentric due to his lack of modern common sense, he wasn't completely oblivious to the atmosphere.

He had intended to work with Fiona and her party today and was well aware that they didn't want to go to the fourth underground floor.

However, having found the emblem of the Sage Dormione, he couldn't turn back.

If this place was indeed the Sage Dormione's research facility, it wouldn't be surprising to find dangerous magical artifacts or weapons underground.

These things must never see the light of day.

He needed to find and dispose of them as soon as possible.

Therefore, he had planned to send Fiona and her party back early and secretly explore the Ainzas underground labyrinth alone.

"Isn't this impossible!? Seriously, isn't this impossible!? Hey, did that old man Lambert really go this way!?"

"But, if it's Lambert, he might be able to handle it..."

"Don't you know about the incident where the guild 'Witch's Candle' sent twenty people in and none of them came back!? This isn't a place to rush in with a small group and no plan!"

The guild "Witch's Candle" was, until recently, the third-largest guild in the city of Ainzas.

It was a famous guild known throughout the Regius Kingdom, not just as an adventurer guild but also as a magical research organization, with a team of excellent mages.

However, that was now just a past glory.

"Witch's Candle" had launched a large-scale expedition to the fourth underground floor of the Ainzas underground labyrinth six months ago, with preparations to retreat quickly in case of an emergency, but no one returned.

Losing the majority of its officers, "Witch's Candle" was subsequently forced to disband.

"I'm not going! I'm not going, I'm turning back! I'll hide somewhere... Yeah, if I join other monsters and rush in, I might be able to slip through!"

Lloyd was stubbornly searching for a way to survive other than going to the fourth underground floor.

At that moment, Lily, who had been standing with her eyes closed and her staff planted, opened her eyes and slowly shook her head as she lowered her staff.

"...They're coming from multiple passages. If we stay here, we'll definitely be surrounded. We don't have much time to think."

"Huh!?"

Fiona took a deep breath and turned to the two of them.

After a small nod, she drew her sword and ran down the stairs to the fourth underground floor without waiting for their confirmation.

There was no more time to discuss.

Fiona decided that it was better to show her resolve through action rather than words to convince Lloyd.

Lily, seeing Fiona's determination, immediately followed her.

"Ah!?"

Lloyd reached out, but he couldn't catch Lily.

Lloyd stood in front of the stairs, watching Fiona and Lily run down, and slumped his shoulders.

Then he stomped the ground roughly.

"Damn it, damn it! I guess we have to go, we have to go!"

Thus, Fiona and her three companions, half in despair, ran down the stairs to the fourth underground floor where Lambert was.

At the bottom of the stairs was a large room.

It seemed that Lambert had already activated a luminescent stone, as the area was now brightly lit.

While the previous floors had the appearance of a decayed old ruin, the fourth underground floor had a different atmosphere, resembling a slightly old palace.

The walls were intricately carved with various patterns, but upon closer inspection, most of these patterns were unsettling, such as flowers with hand-like petals, one-eyed monsters, and eggs with visible wings.

The floor was covered with shallow water that reached up to the ankles.

Fiona and her party were confused but felt some relief when they spotted Lambert.

Lambert was standing in the middle of the large hall, holding his sword loosely.

"Lambert?"

As Fiona approached, a black shadow darted towards Lambert at an incredible speed, almost too fast to see, passing by his side.

"That, that's the... the rumored..."

The "monster that changes shape like a black shadow"... the reaper of the fourth underground floor, no doubt.

"Lambert, that's reckless! Come back!"

The black shadow flew towards Lambert again.

Lambert swung his greatsword with incredible speed. The shadow was cut in half, splattering black liquid as it fell to the ground.

The impact of the greatsword caused the surrounding water to splash up.

"Ah! Did you... did you do it!?"

But one of the halves of the black shadow immediately jumped up from the ground and lunged at Lambert again.

"How, how can it not die...!?"

"Old man! Run!"

Lambert raised his greatsword to its maximum height and swung it down diagonally from his abdomen.

The black shadow was crushed by Lambert's greatsword, making a loud popping sound.

Water splashed up, obscuring Lambert's figure.

As the water cleared, the black shadow was gone.

"Did we... did we get it this time...?"

Lambert squatted down and picked up a crushed, organ-like substance.

"It's a slime, this is its core. It was a bit faster, so it gave me a scare."

"You... you were surprised?"

To Fiona, it seemed like Lambert had calmly crushed it, but hearing that he was somewhat surprised made her feel a bit relieved.

(Even someone as monster-like and strong as him gets surprised... He's still human. I feel a bit more at ease.)

No, he's an undead.

"Old man, is that... a mutated slime...?"

"No, I believe it's a slime that has been modified by human hands. A normal slime would lose a significant amount of its movement ability if it lost half its body, whether it's the core or not. The fact that it could immediately jump up at the same speed is too convenient to be a mutation."

Lily's eyes widened at Lambert's words.

"No way! Creating monsters is the domain of gods or devils..."

"Someone must have stepped into that domain. Since there might be even more dangerous things hidden here, I can't retreat. For the future of the Regius Kingdom, I can't leave such monsters unchecked. I need to dispose of them as soon as possible."

Lambert lowered his greatsword and turned to Fiona and her party.

"Why did you follow? I told you to go back."

"No, some strange people were following us from behind... That's why..."

"...Ah, that's why."

Lambert, being an undead, could sense the life force of animals and knew their positions.

He sensed that some strange people were advancing through the labyrinth in a scattered manner.

However, he didn't consider them a significant threat and wasn't overly cautious.

His mind was preoccupied with the Sage Dormione.

"I'll finish up here soon. Stay close to me until then."

"That's... reassuring..."

Lloyd was surprised by the strength and nonchalance with which Lambert spoke, standing in a dungeon filled with unknown monsters and facing a group of enemies trying to surround them, without any trace of fear or surprise.

"Sorry to cause you trouble..."

"It's fine. I'm a bit on edge and my focus is narrow... Hmm?"

Lambert suddenly stopped mid-sentence, quickly moved to Lily, grabbed her shoulder, and struck her face with his other hand.

"Ah!"

Even the usually quiet Lily let out a scream.

Her hair was disheveled by the force of Lambert's punch.

Lambert's arm, which he pulled back, was covered in black liquid, and in his hand was the crushed core of the slime.

"There are also some hiding in the water below. They're hard to detect when they're in a waiting state, so it's better to stay close together."

"..."

Lily silently nodded twice.

Lambert, keeping his senses alert, continued to move forward.

"Lambert, can we... can we go back to the surface for a moment?"

Lily called out to Lambert's back.

Lambert turned halfway and shook his head before facing forward again.

"I don't want the dungeon's master to realize we've entered here. If they're fully prepared, it will be impossible to break through. Whether it's someone who inherited their will, someone using the laboratory, or just rampaging monsters... I want to finish this today, considering the worst-case scenario."

He resumed his advance.

"This... we might have a better chance of survival if we turn back..."

Lloyd, looking at Lambert's back, muttered in a resigned tone.