The appearance of an unidentifiable plant was certainly beyond expectations.
However, it didn't feel sudden. Osian had sensed that something would happen from the point when pollution levels in the contaminated zone were lower than expected.
The scene before his eyes was merely unexpected as the result, but once faced with it, what he had to do remained unchanged.
-Zhzhezhzeok.
Frost rose around the Moonlight Blade, spreading coldness.
The roots that had been creeping along the floor crumbled from their tips when touched by the cold and the remaining roots had to hastily retreat.
The water they had poured to resist the fire had instead become their undoing.
Osian created a kind of boundary line with the frost.
"I forbid you from crossing any further."
It wasn't the plant but Mist who responded to Osian's words.He perked up his ears and listened intently to Osian's words.
'That's cool. I should use that line later.'
The plant, which had been trying to gradually expand its range, retreated under Osian's spirit, but soon began pushing forward with stronger and thicker stems.
Even the Moonlight Blade's cold couldn't freeze such large and thick stems at once.
The stems crossing the boundary of cold were cut down by blue flashes.
"It seems my warning was taken as a joke."
Osian observed the plant's movements. The stems searching for living beings seemed to intend to use them as hosts for reproduction.
'Plants in the underground waterway.'
The lowered pollution levels in the contaminated zone were probably this thing's doing.
While the contaminated zone was difficult for living beings to survive in, it didn't deliver an equal death to all.
As seen with mutant rats or ethereal snakes, such pollution sometimes causes certain specimens to evolve even stronger.
It wasn't strange that plants, which should originally die while absorbing and purifying pollutants, would undergo a similar process.
It was a product of chaos that no one had intended.
'What's most concerning is its formidable reproductive ability.'
Just by stabbing tree branches into a human body, it achieved explosive growth by instantly using it as nutrients.
In other words, allowing even a slight attack from it would mean following the same path as the victim seen earlier.
'Moreover, what needs extra caution is that while it's a plant, it has its own intelligence.'
It initially induced carelessness through the vagrant, then controlled the vagrant's body to stab tree branches into the guard's body.
Just from that, one could tell it was capable of controlling parasitized life forms and had enough intelligence to set traps.
Among these, what irritated Osian's nerves the most was the fact that even this wasn't its main body.
'It reproduced using living beings as nutrients. But fundamentally, what could be called its core hasn't even appeared yet.'
The one here was, strictly speaking, nothing more than a mass-produced product through reproduction.
Yet it showed such powerful individuality.
'Moreover, it seems to be strangely targeting Mist and me.'
In particular, there were quite a number of tree stems subtly wiggling toward Mist.
"You'd better be careful. It seems to be targeting both of us."
"What do you mean?"
"It senses that we both have particularly abundant nutrients to absorb."
"That makes perfect sense."
Even just the mist that Mist controls has considerable energy. Probably this plant intends to absorb all the source of mist within his body.
"Then we definitely can't let that thing be."
"The problem is that even if we deal with this one, there might be more after it."
Osian informed him that this was merely a mass-produced specimen, and the main body was elsewhere.
Mist's gaze turned to the plant preparing to attack.
"Even knowing that, the question is what to do about this one."
Usually, he would have fought first and thought later, but they weren't alone here.
Behind them were guards, city officials, and contractors.
Once the fight starts, they would inevitably get caught up in it.
Osian decided to retreat for now.
This wasn't an extermination mission. Safe return was more important than defeating the enemy.
"Can you buy us some time?"
"That's perfectly doable."
Mist unwound the bandages on his arms a bit more.
More gray mist flowed out from between the bandages.
The flowing mist moved along both walls before becoming a thick wall blocking the entire passage.
Sensing that this side was trying something, the plant moved. The thick stems it had prepared moved and pounded against the mist wall.
-Thump! Thump! Thump!
The sound of plants pounding echoed dully beyond the hazy mist wall.
The mist wall stretched long like elastic rubber before returning to its original form repeatedly.
'Not only is it powerful for attacks, but it's also definitely effective for defense. It's a very versatile ability.'
However, looking at Mist's trembling hands, it didn't seem like he could hold out for long.
"It's breaking through."
With Mist's warning, part of the mist wall stretched long before tree stems tore through it left and right.
Though the stems were split like firewood by Osian's Moonlight Blade as soon as they emerged, there weren't just one or two of them.
"Everyone fall back."
At Osian's warning, the people who had been watching the fight moved hurriedly.
They instinctively felt that if they stayed here any longer, they would get caught up in the fight and be devoured by that plant.
After confirming that people were retreating, Osian asked Mist.
"Would it be alright to freeze this mist?"
"You seem not to know, but my mist isn't ordinary mist. It doesn't freeze well even with ice magic and is hard to evaporate even with fire."
Mist's words weren't false.
The mist he controlled was on a completely different level from ordinary mist that forms when water becomes vapor.
"To freeze that..."
Before Mist could finish speaking, Osian's Moonlight Blade pierced the mist wall.
Intense cold swirled around the Moonlight Blade that had sunk in with a thud.
The power of the Moonlight spread through Mist's mist wall, freezing it in its shape.
"My ice isn't ordinary either."
When the wall froze, the plants hitting it froze along with it.
Using the mist as a medium to spread the cold, the power of moonlight showed efficiency several times better than before.
The fact that Mist's mist wasn't ordinary had a big impact. If it were ordinary mist, it should disappear when frozen, but Mist's mist froze while maintaining its form.
This meant its density and properties were beyond common sense compared to what was visible.
"This can't be."
Mist was shocked by Osian's power that easily froze his mist.
"How did you just do that?"
"There's not enough time to explain. Let's retreat for now. It won't hold for long."
Osian detected the movement of plants stirring beyond the ice mist wall.
"It seems that thing has properly marked us as prey."
"..."
Since Mist felt it too, he joined the retreat instead of arguing.
The two chased after the group that had gone ahead.
"They're coming! They're coming!"
"Thank goodness you're safe!"
Relief appeared in the eyes of the people who saw Osian and Mist.
Without these two, who were the strongest forces here, they would be as good as dead.
Adela urgently asked the contractor guiding the way.
"Where's the nearest exit?"
"Uh, if you go about 3 blocks from here and turn right once, there's a door that leads up!"
"What are you hesitating for? We need to go that way now!"
"B-but that's within the contaminated zone's influence..."
"This is no time to worry about that!"
Since the plant was blocking the path leading outside, they had to go deeper into the contaminated zone instead.
Though they knew it was dangerous, they had to trust the contamination levels shown by the measuring device.
"Everyone put on gas masks just in case!"
Though gas masks alone couldn't withstand the contaminated zone, they wouldn't feel at ease without doing at least this much.
However, such worries disappeared the moment they saw the passage showing no signs of any contaminants.
Adela, who had been somewhat tense, muttered without even thinking of removing her gas mask.
"Has the contamination really been purified?"
The measuring device wasn't wrong.
Whatever it was, this was an opportunity.
The group quickly ran toward where the exit was.
That's when a rumbling sound and the noise of something collapsing echoed from behind.
The people who had been running well turned their gazes back with a start.
Beyond, they could see tree stems surging like a tidal wave through the passage.
"I-it's coming! It's coming!"
People's faces turned pale.
"Mist!"
Osian called out Mist's name.
'Damn it! Don't casually call a senior's name!'
Mist internally complained about such behavior from Osian.
The mist flowing from both his arms formed another wall.
Osian froze that wall again with his Moonlight Blade.
-Kwang!
But looking at the impact force on the ice mist wall, it didn't seem like it would hold for long.
"Hurry up and climb!"
The people who reached the exit tried quickly to open the door, but the creaking door showed no signs of opening.
"What are you doing!"
"It-it won't open!"
"What's going on!"
"Ah, it seems the door is broken from being unused and neglected for so long..."
That's when Hammond pulled the guide's shoulder.
"Move!"
Hammond took out his favorite weapon. It was a portable cannon so heavy that even he, a mana user, had to hold it with both arms.
"If it won't open, we'll just break it!"
The cannon spewed flames and hit the door. Everyone had to cover their faces with both arms from the explosion's impact.
The explosion's smoke settled. The expressions of people who thought it would have been enough to break through turned to despair.
"H-how. Even my weapon didn't make it budge."
The door was intact except for scorch marks from the explosive flames.
The contractor who had been forcibly pulled aside by Hammond spoke with a tearful voice.
"Th-this place was built more solidly than other underground passages since it's installed in the contaminated zone. It was made to not budge even with considerable bombardment..."
People despaired at the fact that there was no way to physically open the broken door.
One might think they could go to doors elsewhere, but the possibility of being caught by that plant during the journey was higher.
That's when Osian stepped forward.
"Move aside."
Osian released the Moonlight Blade and instead drew the Starlight Sword.
The Starlight Sword, burning stronger than before, was sharpened keenly and thrust toward the door.
"That won't..."
Before the guide could finish shouting, Osian's sword slowly melted through the metal door and dug inside.
The door that hadn't budged even to explosives was being pierced.
With that, Osian slowly moved his sword along the door's outer line.
The resistance was too strong to move quickly. Apparently, they hadn't used ordinary metal to prevent contamination and corrosion from the contaminated zone.
The thickness was also ridiculous. It was literally no different from a bomb shelter.
Conversely, this meant Osian was cutting through a bomb shelter-grade door with just one sword.
'Just a little more.'
Just as he was about to cut through the door, Mist shouted from behind.
"Hey! How long will it take?"
This time there was no room for acting or anything else to be urgent.
Because the mist walls he had created multiple times couldn't withstand the plant's offensive.
"One minute. No, less than that."
Mist tried to create another thicker wall with mist again, but the amount of mist coming from his arms had decreased more than before.
Mist clicked his tongue and bit his lip, then pulled out a bottle containing a pure white liquid from his waist.
Mist lowered the cloth around his mouth and drank the liquid.
'What did he just drink?'
It clearly didn't look like an ordinary potion.
Mist's body twitched momentarily as if in pain but the mist flowing from his arms increased more than before.
Not just from his arms, but thick mist was flowing from his entire body.
The mist wall became even more solid. The plant's advance was finally stopped.
"Good. At this rate, about a minute..."
Just as Mist was muttering that, his expression changed.
The plant's attacks beyond the mist wall had gone quiet.
Did it give up after realizing it couldn't break through? No, that couldn't be.
'If not that, then why?'
The reason was soon revealed.
A bright yellow light began flickering at the center of the mist wall.
Right after, the center of the mist wall collapsed, and a bright yellow beam swept across the ceiling of the underground waterway.
-Kuwagwagwagwak!
"Kyaak!"
"Uwaah! What is this!"
A high-heat beam passing across the ceiling along with dazzling flashes.
Osian saw a huge flower bud aiming this way beyond the mist wall with a hole blown through it.
That's it.
He could feel it instinctively the moment he saw it. The main body that had caused this anomaly in the contaminated zone had come here.
'More than that, that power...'
What he had just seen was a power that felt somehow familiar.
"Hey! Anyone there, move aside! Don't blame me if you get caught up in this!"
Just then, as huge energy writhed beyond the door Osian had almost broken through, a warning came from beyond the door.
No sooner had Osian moved away from the door than it fell off with an explosion.
-Teong!
Hot flames flickered beyond the fallen door.
'Flames?'
The flames moved along the walls like living creatures and rushed toward the plant.
-Keeeeek!
The plant that touched the fire writhed in great pain. It was an unusually sensitive reaction.
'These aren't ordinary flames.'
Osian's gaze caught something dwelling within the flames. It was a lizard made of flames.
It was so well camouflaged with the fire that it would be hard to spot without careful observation.
'A fire elemental.'
Moreover, that elemental looked familiar, as if seen somewhere before. One might say most elementals look similar, but this one was different.
"Hey, is everyone alright?"
Along with the familiar voice, an elf appeared through the broken door.
Unlike other elves, she was an elf with healthily tanned skin and a sturdy build.
Blacksmith Eldin appeared with a hammer slung over her shoulder.