As long as the reward is guaranteed....
I carefully scanned the bolded trade listings on the exchange.
Most were difficult or had annoying conditions, but I spotted two that looked easy enough for me to clear.
---
[Deliver 5 unopened old boxes.]
- Reward: 1 Random Stat Increase Potion
[Hunt plant-type monsters in the poisonous fog zone around Siheung Neunggok Station and collect 30 venomweed.]
- Reward: 1 Skill Evolution Stone
---
"An unopened treasure chest, huh."
Normally, survivors would have a hard time even finding chests, and even if they did, they'd probably open them on the spot because they were so bulky.
After all, keeping five unopened ones in storage would be quite a burden.
But I had my reliable drones.
"Just bring me five boxes from nearby like usual."
Whirr.
The two of them shot out of the train.
They'd probably be back in less than an hour, having stacked the five boxes into a tower.
The first trade was practically free.
"Now then, the second trade post is the real problem..."
The real target was the second post.
I entered the destination into the cockpit panel.
According to the current trade post, an unidentified toxic fog seemed to be spreading near Siheung Neunggok Station.
After searching the gallery for more information, it seemed the post was telling the truth.
There was a post from a nearby user saying they'd seen green fog.
"So there were posts like this..."
Once the gallery's user count grew, I only picked out the information I needed, so I'd carelessly overlooked posts like that.
"Poisonous fog, huh... it won't seep in through the gaps in the train, right?"
Whirr—
Just then, the drones came in carrying the five boxes between them and tapped the door as if to say not to worry.
It seemed to mean that as long as I kept the doors properly secured, we'd be fine.
"All right, let's go."
Before setting off, I turned in the five unopened treasure chests the drones had brought back from the second-car hangar to the trade post.
The bold text on the screen flashed, and the reward immediately dropped in.
[You have met the trade post conditions.]
Whoosh!
A potion that increased a random stat suddenly fell from the air.
Fortunately, I caught it in midair.
It was a potion with a purplish tint, a color that made it a little hard to bring myself to drink.
"...Let's drink it."
When I cautiously drank the potion, a fragrant grape scent spread through my mouth.
"Huh? Could this just be grape juice—"
Then a message window appeared.
[Agility permanently increases by 1.]
"Phew..."
Thankfully, it wasn't a lie.
Agility looked like a stat that would help with escaping or attacking, so I was satisfied.
Having picked up a decent amount of stats, I immediately steered the train toward my next destination, Siheung Neunggok Station.
Rumble—!
As we headed south, the scenery outside the window changed.
As we left the ashen city behind and descended toward the tracks, a murky green fog began to wrap around the train.
The outer walls of apartment buildings were tightly wrapped in thick giant vines, and bizarre plants that had grown through the asphalt waved disgusting tendrils.
"That’s a monster too, I suppose..."
Sssssh—
As the train entered the boundary of the poisonous-fog zone, the fog hissed against the train's outer armor.
Of course, it was only a sound; there was nothing wrong with the train itself.
[Warning: High level of external air pollution.]
[Activating the internal air purification system.]
[Interior air: Very pleasant (99.9%)]
The air conditioner turned on automatically.
I breathed in the cool air from the train's AC.
Outside the window, the poisonous fog spread faintly, but inside the train it was comfortable.
"That's a relief. Let's see..."
I slowed down and carefully observed the scene outside the window.
"Oh, is that it?"
Beyond the fog, beneath a bent streetlamp, I could see clumps of grass emitting fluorescent green light.
Giant Venus flytrap-like creatures as tall as a person were surrounding the fog-spewing grass like guards and dripping sticky sap.
They looked threatening at a glance.
For an ordinary Awakened, having to fight those monsters while barely able to breathe because of the poisonous fog would be hell on earth.
"Eliminate the plant-type monsters in the area and gather venomweed for me."
Whirr—
The hangar opened, and the two drones flew off as if dissolving into the purplish fog.
I focused on the drone camera feeds being transmitted to the monitor.
"Wow... this place is really... a wreck."
The scenery beyond the screen was horrific beyond words.
Huge wild-dog and animal-type monsters that would normally have roamed the streets threatening survivors were sprawled on the pavement, trembling.
It looked like quite a few monsters had already died.
Now and then, I also saw scenes where only mana stones and items were left lying on the ground.
"Oh, man..."
Even more horrifying were the traces of people.
All over the place were the bodies of pitiful people who seemed to have collapsed after trying to escape the fog, frozen stiff while clutching their luggage.
It couldn't have been easy for people to survive poisonous fog that even monsters could not withstand.
But paradoxically, there were also places that had been preserved thanks to that poisonous fog.
"...Most of them haven't been looted."
Inside the glass windows of the large mart and convenience stores the scout drone passed, food and daily necessities were still neatly displayed, just as they had been before the apocalypse.
Places untouched by survivors.
Of course, since they'd been exposed to the fog for so long, I was a little worried whether they were still in usable condition.
"I'll check those later. For now, let's deal with those guys."
The scout drone turned its camera toward the flower bed of a collapsed commercial building.
The combat drone aimed at a mass of plants that looked like monsters in the thick fog.
"Fire."
The moment my command was given, the combat drone sharply dropped altitude and aimed its silenced submachine gun at the target.
Tutututung—!
Muzzle flashes cut through the fog as the rounds flew.
Thump! Thump!
A few of the plants spotted the drone and spewed acid, but there was no way the sluggish attacks of plant monsters could ever reach a machine drone flying through the sky at high speed.
Sharp bullets and lasers mercilessly tore apart their thick stems and maws.
Splurt! Crack!
The plants collapsed pointlessly, bursting green sap everywhere.
In front of the drones, they were nothing but slightly tough weeds.
Since the poisonous fog was their main attack, their own bodies seemed to have very poor durability.
"They’re a good matchup."
Once the situation was over, the scout drone landed lightly and extended its claw.
From their corpses, along with mana stones, the venomweed mentioned in the trade post seemed to drop at a high rate.
"That makes five... Now gather 30 of this venomweed."
As if it were nothing, the drones immediately went off to hunt another cluster of plants.
Forty minutes later.
The drones safely returned to the train with 30 venomweed and the mana stones in tow.
Just in case, I left the venomweed in Car 2 and checked the trade post from Car 1.
"Let's see... the reward..."
As soon as I sent the freshly harvested venomweed, the bold-faced trade post flashed and a system message appeared.
[You have fulfilled the trade post conditions.]
[Reward received: 1 Skill Evolution Stone]
A jewel shimmering with a radiant rainbow light dropped down from above my head.
"This is it."
I decided to use the Evolution Stone right away.
Repair or vitality would have been appealing too, but this train was ultimately responsible for 99% of my survival.
Without hesitation, I brought the Evolution Stone to the train skill.
[Using the Evolution Stone.]
Fwaaaah—!
A massive light swallowed the entire train.
Last time, only the engine's efficiency went up, but this time it was different.
The train shook violently, and a tremendous roar rang out as if its frame were being rebuilt.
[The train's exterior has been reconstructed, and new modification functions have been unlocked.]
"...The inside hasn't changed much."
There was nothing particularly different inside after the light faded.
The changes were in the exterior.
The train's armor plates had transformed into smooth, elegant curves, as if they had been carved from obsidian.
Each seam in the armor had been painted with a subtle gold sheen, adding to its luxurious feel.
"The appearance is one thing, but..."
[New modification: Off-track driving mode]
[New modification: Stealth shroud]
[...]
"It can run without tracks, and even turn invisible?"
It perfectly covered the train's one and only flaw: limited mobility.
And on top of that, the stealth function would be useful in many ways.
The problem was—
- Modification cost: 100 high-grade mana stones, $5,000 dimensional credits, 10 years' worth of fuel.
"..."
I quietly closed the modification window.
100 high-grade mana stones? 5,000 credits?
It was the moment my past self, who had been delighted to pick up a few dozen lowest-grade mana stones with the monster lure, felt utterly pathetic.
"Yeah, well... following the tracks is enough for now."
Just as I was about to soothe my disappointment and flop onto the sofa,
Bzzzzt—!
"Huh?"
Suddenly, a blue window appeared before my eyes, crackling with static.
It wasn't an alert from the Survivor Gallery, nor a system notification from the train.
Just like when I opened a status window, a blue screen blocked my view.
Authoritative, alien text began appearing one character at a time in the air, as if typed on a typewriter.
"W-what is this..."
[The Swamp Observer is intrigued that you completed this trade without a scratch.]
[Looking forward to your next move, an additional 30 low-grade mana stones have been awarded.]
Thud-thud-thud—!
The moment I finished reading the message, 30 low-grade mana stones really did rain down from the air and roll across the train floor.
"Huh..."
I swallowed hard, glancing back and forth between the mana stones on the floor and the message window that had suddenly appeared.
It was an incredible bonus reward, but I wasn't purely happy about it.
The conspiracy theory circulating in the Survivor Gallery.
The constellation theory.
That might actually be true.
"I've seen this scene somewhere before..."
It felt strange experiencing a scene I'd definitely seen somewhere before—in a webtoon or a web novel—in real life.
I let out a dry laugh as I checked the mana stones scattered on the floor.