The Namsan Monster Defense Tower is one of the key facilities in Seoul’s defense strategy.

The steel tower is equipped with 24 ten-round short-range anti-air missile launchers. To intercept flying monsters that manage to break through that missile defense network, there are also four 20mm close-range anti-air Gatling guns.

The 240 short-range anti-air missiles in a constant standby state and the four anti-air Gatling guns are not offensive weapons. They are all for defending the tower.

What this defense system protects are the four long-range sniper railgun turrets and the four phased array gate detection radars protruding from the middle of the steel tower.

The long-range sniper railguns are not meant for small targets but for large monsters impervious to regular bullets.

Even more important than those railguns are the gate detection radars.

In the world he lived in, people referred to spatial rifts as “gates opening.” Monsters emerged from these gates, crossing over from another world.

The earlier a gate is discovered, the more damage can be mitigated. That is why people built a steel defense tower on Namsan and installed gate detection radars on it.

But the Seoul Tower that Seo Jung-woo was looking at had neither long-range sniper railgun turrets nor a single short-range anti-air missile. Instead of missiles, a round observation deck for tourists was visible.

He analyzed the situation.

“Wait, hold on. That’s the real Namsan Tower. Right up until I used my teleport skill, there was definitely the Namsan Monster Defense Tower there, but now it’s turned into Namsan Tower.”

He turned to look around.

Far beyond the Han River, a golden skyscraper that should have only existed in his memories stood tall.

“Wow. This is insane. That thing definitely collapsed!”

Seo Jung-woo had taken part in the Yeouido Defense Battle when that building fell.

Even Awakened individuals with special abilities received military conscription orders like everyone else. He had been assigned to the Awakened Special Forces on the very day he enlisted, skipping boot camp entirely. At the time, the war situation was too dire to afford to keep combat-capable soldiers in training. He had been immediately deployed to the Yeouido Defense Battle.

And just ten days later, he had witnessed that building collapse firsthand under a drake’s aerial assault. Back then, Korea had lost Yeouido to the monsters. Seo Jung-woo had barely escaped with his life.

That land had once been a fierce battlefield against monsters.

Now, though the monsters had been pushed out, the gate destroyed, and Yeouido reclaimed, no one built skyscrapers like that anymore. Every new structure in Korea was low-rise.

Yet here, the golden skyscraper that had once fallen still stood.

“Where the hell am I?”

He scanned his surroundings. Even the cars looked different from those in his world.

“For god’s sake. Not a single armored vehicle. They’re all just thin steel plates.”

His wandering eyes landed on a poster stuck to the bank’s wall.

“A 2018 event? So at least I haven’t gone to the past. This is the present?”

But this place was vastly different from the Seoul of 2018 that he knew.

A hypothesis came to his mind.

“Could this be… a parallel dimension?”

Some scientists had theorized that when a gate opened, it temporarily linked Earth to a monster’s dimension. This was known as the Dimensional Gate Theory.

Other theories claimed that gates didn’t lead to other dimensions but rather to different planets, akin to a Stargate.

Some extreme theories even suggested that gates connected Earth to hell.

Many theories had surfaced, but the truth remained unknown. Among them, the Dimensional Gate Theory and the Stargate Theory had the most support.

“So the new skill I Awakened… wasn’t just a teleport? It’s a dimensional teleport skill that moves me between parallel dimensions of Earth?”

Having lived in a world invaded by monsters through gates, he had no trouble accepting the idea of parallel dimensions.

He turned and re-entered the bank.

Inside, people were in the middle of tying up the bank robbers when they flinched in alarm at his sudden return.

“Hrk!”

Some of them still harbored concerns that he might be insane. After all, he had stolen from the bank robbers, then screamed outside about why Namsan Tower was in Namsan.

And now, the lunatic had come back inside.

The bank manager, mustering his sense of responsibility, hesitantly stepped forward. His voice trembled.

“W-why have you come back…?”

Ignoring them, Seo Jung-woo opened the bank’s restroom door. There was no gate.

“How do I get back to my original world?”

Using the skill again was the simplest solution.

He wasn’t worried about returning. He recalled theories about monster invasion gates.

“Since the monsters’ world and our world are always stably connected, this place must also be linked to my original world.”

Gates could link to multiple worlds, but the same type of monsters always came from the same world. Scientists believed this was because the spatial coordinates used to open gates remained fixed.

Following that theory, if he used his dimensional teleport skill again, he should be able to return to his original world.

However, teleport-type special skills had long cooldowns, making consecutive use impossible.

He checked the skill’s status. Though it didn’t display numerical values, he could estimate based on intuition.

“Recovery rate… around 4% per hour?”

Even with rough calculations, it would take at least a day before he could use the skill again.

“I’ll have to stay in this world for at least a day.”

He stepped out of the bank’s restroom. The people inside were still frozen stiff.

He asked, “Have you called the police?”

The manager explained, “T-the robbers destroyed the emergency alarm, the security cameras, and all the other security equipment, so we still haven’t….”

“So cell phones are just for show, huh.”

“The robbers smashed all the phones too…”

“Then go outside and call from another store’s phone.”

“C-Can we really do that?”

“It’s not about whether you can, you obviously should…”

Seo Jung-woo suddenly remembered the two shotguns slung over his shoulder.

‘Ah. The guns.’

He had taken down the robbers with his pistol.

‘Back in the day, firing a gun recklessly was a big no-no.’

Before January 1, 2000, when the gates opened and monsters started invading, South Korea was a country where gun possession was prohibited.

‘Now I get why the bank robbers only had shotguns. Gun possession must still be illegal in this world.’

In countries where firearms are banned, even a robber wielding an air gun is a serious threat.

And then, he realized his own predicament.

‘If the police arrive, I’ll be arrested too, won’t I?’

Seo Jung-woo touched his face. He was wearing goggles and a protective mask. At best, it resembled a special forces mask; at worst, it looked like a bank robber’s disguise.

“Oh. Well then… I’ll be on my way. Good work, and let’s pretend we never met.”

“Huh? Ah. Yes!”

“Ah. The guns. I don’t even need them. Hahaha!”

Seo Jung-woo placed the two shotguns on the floor.

They were unmodified, low-power shotguns—too weak for him to use. Originally, he planned to sell them off.

But in this world, selling firearms wasn’t as easy as in his. Carrying around a gun that was worth little would only put him on the police’s wanted list.

“I’m even leaving the guns behind, so don’t bother putting out a warrant for me. I didn’t do anything wrong. I saved you, didn’t I? Right?”

The people instinctively nodded in unison.

“That’s right!”

Waving at them, Seo Jung-woo slipped out the bank’s back door.

A customer approached the shotguns.

“The robbers might wake up, so I should take the gun…”

A bank employee quickly ran over and grabbed the shotgun, suspecting the customer might be an accomplice.

“W-We bank employees should be the ones to… no, I mean, we’ll protect the customers with these. Protect! Don’t step back so suddenly!”

The customer flinched and shouted.

“Take your finger off the trigger! And point the barrel up! If it misfires—”

The bank employee hastily raised the barrel but accidentally pulled the trigger.

The shotgun fired, filling the bank with a deafening blast. The buckshot shattered the ceiling lights, sending pieces of gypsum board raining down like snow.

The employee screamed.

“A-Aaaah! Why did that happen?!”

“I told you to take your finger off the trigger!”

Seo Jung-woo walked into a side alley outside the building.

“The CCTV here looks pretty much the same.”

His world also had CCTVs. When a gate opened nearby or a monster emitting strong electromagnetic waves appeared, the sensors burned out, but their usefulness was so great that they kept getting replaced.

In his world, image sensors for CCTV had built-in EMP protection as a basic feature. That increased the chances of the sensors surviving.

Avoiding CCTV was easy for him.

He had infiltrated monster-infested zones before—evading a few obvious cameras was nothing.

Moving between alleys, he found a clothing donation bin tucked in a corner.

“A donation bin? People just throw away clothes here?”

He reached inside and grabbed an outfit. When he pulled it out, it was perfectly intact.

“It’s not even torn. Why would they throw this away?”

Without hesitation, he emptied the bin and changed into fresh clothes. He even found a bag inside. He stuffed his combat gear, mask, pistol, spare magazines, and other equipment into it.

Now, wearing different clothes and carrying a bag, he blended in perfectly with the people of this world.

He stepped onto a busy main street, carefully observing and analyzing this dimension.

“No ruined buildings, no one carrying guns, no shelters, no mounted machine guns on street corners, and so many cars. Wow. There are so many cars.”

What impressed him even more were the towering skyscrapers.

“How many floors is that? There must be dozens of them! Why are there so many high-rises?”

In his world, skyscrapers were no longer built. If a battle with monsters caused one to collapse, the owner would go bankrupt.

The only tall structures built were defensive towers like the one on Namsan or industrial reaction towers in factories.

Seeing the countless high-rises, Seo Jung-woo was certain.

“This dimension hasn’t been invaded by monsters.”

In his world, the first gate opened on January 1, 2000, unleashing monsters onto Earth.

Humanity successfully defended against the initial invasion. At first, they were caught off guard and suffered heavy losses, but the military managed to hold them off with sheer firepower.

However, the gates kept opening. The monster invasions never stopped.

The Gate War in his world was still ongoing.

He had to wait a full day before he could return. Only an hour had passed.

Seo Jung-woo strolled through this world, taking in the sights.

“This place is so peaceful…”

He stopped in his tracks, staring in shock at a huge sign in front of him.

“T-They’re selling beef in restaurants? No way, they’re serving that precious stuff in restaurants?!”

In his world, the livestock industry had vanished. If even the lowest-tier gate opened near a ranch, all the cattle would be wiped out. If a single monster broke into a pig farm, the entire place would be ruined.

Some rare facilities managed to raise a handful of cows under strict security, but their meat was so expensive and rare that it never entered the market. Ordinary people couldn’t dream of eating beef at a regular restaurant.

Yet this restaurant was offering a buy-one-get-one-free deal on beef.

“Is this world full of scammers?”