Seo Jung-woo boarded the bus home. The subway was mainly used for tactical movements and was also expensive.

Many high-rise apartments had collapsed due to monster attacks, and none were being rebuilt. There were still quite a few remaining, but they were not popular.

Nowadays, even when buildings were constructed, they rarely exceeded five floors. If a taller building collapsed, the damage would be too great.

The house where Seo Jung-woo and Seo Sora lived was a single-story home.

He opened the thick iron door and stepped inside.

Seo Sora came down from the attic.

“There was no tail.”

Seo Jung-woo thought of the Seo Sora from the other world he had just seen. She had the same face as the one standing before him now, but her attire was completely different. The Seo Sora here was wearing combat gear.

Seo Jung-woo let out a small sigh.

‘Our Sora should be living like that too.’

“It’s not a situation where I’d be followed.”

“Oppa, your skill has some kind of anomaly, doesn’t it? I noticed when you couldn’t explain it properly over the phone.”

“You're the only one who noticed. To others, it just looks like a teleportation skill.”

“Huh? It’s not teleportation?”

When Seo Jung-woo first used his newly awakened skill, he vanished right before Seo Sora’s eyes. A few minutes later, he contacted her from the location of their old home. In her understanding, such a skill could only be teleportation.

“At first, I thought it was teleportation too, but it’s a bit different. I can’t designate coordinates. The skill activates and moves me instantly.”

“I figured as much. That’s why you disappeared without any preparation.”

Even when one awakened a skill, they wouldn’t automatically understand its full mechanics. It had to be tested and experienced firsthand.

Seo Sora tried to comfort him.

“Oppa, it’s okay. Even if you can’t input coordinates, it’s not a dud. At least you can use it as an escape mechanism when isolated.”

“It’s not a dud. It’s a jackpot.”

“Huh?”

Seo Jung-woo opened his bag and started taking things out.

Seo Sora’s eyes widened.

“Oh my? Is this… real meat?”

“It’s beef.”

“Huh? That expensive beef, this much of it?”

He took out another item from his bag.

“Instant rice? Oh my. Real rice? And it’s white rice? Someone actually makes instant rice out of this expensive stuff?”

Seo Jung-woo continued pulling out food from his bag—items taken from the pantry and refrigerator of his home in the other world.

There were canned tuna, Spam, and even ready-made meals.

Seo Sora tensed up.

“Oppa, did you teleport into some chaebol’s food storage and loot it? You stole from there, didn’t you? Oppa, you can’t do that! They’ll track you down! Is that why you couldn’t explain over the phone?”

She picked up her sniper rifle and started heading up to the attic.

“I’ll check again to see if anyone’s following you!”

“It’s not like that. The food is safe. I didn’t steal it from someone’s home.”

“That’s impossible. Then where did all this expensive food come from?”

“Our house.”

“Huh?”

“I brought it from our home in a parallel dimension.”

Seo Sora blinked.

“What are you talking about…?”

“My skill. It’s not just a spatial movement skill. It lets me cross over to an alternate Earth in a parallel dimension.”

“Huh?”

“It’s true. Over here, I was gone for just a moment, right? But over there, I spent a full 24 hours before returning. I think the time coordinates remain fixed when I come back. Even though I spent a whole day there, I returned at the exact moment I left.”

“Ah…”

Having lived in a world where gates opened and monsters invaded, Seo Sora was familiar with such theories at a common-sense level.

She no longer doubted him.

Instead, her curiosity shifted.

“Oppa, then… how much of this kind of food exists over there?”

“It’s everywhere.”

“Huh? How is that possible?”

“Because in that world’s 21st century, no gates ever opened, and no monsters invaded.”

“Ah!”

She realized something crucial.

“Then… it’s not dangerous over there?”

“Yeah. People don’t even carry handguns.”

“Aren’t they worried?”

“Not at all.”

“So you went to a place like that… That’s a relief.”

She finally relaxed. And as she did, she felt her appetite returning.

“Let’s eat first!”

Microwaves were essential even in this world.

They heated up the instant rice—made from real white rice, not synthetic grains—and fried some Spam in a pan.

Spam also existed in this world. It was convenient to eat during battles and packed with calories.

But Spam made from monster meat was tasteless.

Seo Sora took a bite of the steaming white rice. It was delicious.

Memories surfaced of eating such rice when she was very young. Even in this world, she had opportunities to eat rice once every few years, but it was always brown rice.

White rice tasted completely different.

She picked up a piece of Spam and took a bite. Her eyes widened.

This was the first time she had tasted Spam that was so oily, savory, and full of umami.

She alternated between rice and Spam, tears welling up in her eyes.

“It’s so good. It’s too good.”

“Real pork Spam is supposed to taste good.”

Seo Jung-woo opened all the side dishes he had taken from the other world’s fridge.

“Eat these too. They’re all delicious.”

“Okay!”

The beef wasn’t even cooked yet. He wanted to let her experience a variety of flavors first.

“We’ll grill the beef for dinner.”

The two of them each ate three servings of instant rice until they were full.

Seo Sora patted her stomach.

“I can’t eat anymore. If I do, I’ll die.”

Seo Jung-woo opened a bottle of cola and poured it into a cup. Bubbles fizzed up in the dark liquid.

“Try this.”

Seo Sora took a sip without hesitation.

Her eyes widened again.

“Oppa, how can a drink taste this good? What is this flavor?”

Seo Jung-woo smirked.

“The taste of peace, only found in a world without Bug Monsters. Cola.”

“Oh! This is that cola from the novels? Wow!”

“Drink as much as you want. I can always get more.”

Seo Sora hesitated.

“Can you return to that parallel world?”

“I think so, but I’ll have to check. The cooldown period is about 24 hours, so I’ll know by tomorrow.”

“What if you end up in a completely different dimension? It might be dangerous.”

“This skill is too valuable not to test.”

“Still…”

Seo Jung-woo spoke firmly.

“Don’t worry. The time coordinate stayed constant. Since I returned safely, the link between dimensions is stable. Only the spatial coordinates change.”

“Then… this time, let’s go properly armed. Last time, you were too under-equipped.”

“That’s just because I flipped past it while trying to figure out what skill it was. Don’t worry.”

He took out a new gift from his bag.

“Here. These are cosmetics.”

“Oh my, the bottles look so luxurious.”

One after another, cosmetics came out of the bag.

“Wow. There’s so much?”

“I don’t know much about them, but they should be perfect for your skin. Since they’re the ones you used in that world.”

“Huh?”

“There’s a Seo Sora in that world too.”

“Ah, since it’s a parallel dimension... But is it really okay to bring them over like this?”

“If they run out, I’ll just buy more. That world has plenty of cosmetics.”

She smiled brightly.

“My friends are going to be jealous.”

“You know you can’t show them the bottles, right?”

“Of course. I’ll only use them at home. When I go out, I’ll transfer some into another container.”

There were good cosmetics in this world too, but they were all handmade, with limited supply and extremely high prices.

Since they were already talking about friends, Seo Jung-woo asked,

“By any chance, do you have a friend named Yoon Nana?”

“No, I don’t.”

“Figures.”

“Huh?”

“You two got close because you were trainees from the same neighborhood, not the same school. But that neighborhood was destroyed and rebuilt, so the Yoon Nana from this world probably moved away.”

There were worse possibilities, but if possible, he hoped the Yoon Nana from this world was still alive and well.

“Oppa, who are you talking about?”

“Seo Sora’s friend from the other world.”

For dinner, they grilled beef.

Just as Seo Jung-woo had done at first, Seo Sora carefully grilled 1kg of beef with great dedication and ate all of it.

While eating, Seo Jung-woo discussed their future plans with Seo Sora.

Seo Sora said,

“It’s best not to tell Mom and Dad about your ability for now.”

“You don’t trust our parents?”

“I do. I trust them, but I don’t trust the alcohol they drink.”

Their mother worked in the government’s monster response division. Their father was also a government official. Currently, both were stationed in Daejeon, not Seoul.

Alcohol was common in this world too. Though it wasn’t made by fermenting grains or fruit, but rather by mixing ethyl alcohol with water and adding artificial flavors, it still got people drunk just the same. If they got drunk at a work gathering and let something slip, the government might find out about his ability.

Just because they were at war with monsters didn’t mean there were no power struggles or conspiracies. In many cases, people skipped the talking and went straight for their guns. Even Seo Jung-woo himself always fired his bullets first when fighting an enemy.

He agreed that he should keep his ability a secret for now. The only one he could trust not to leak it, even by accident, was his younger sister.

Seo Jung-woo nodded.

“Since they’re stationed in another city anyway, as long as we don’t say anything, they won’t notice.”

That night, Seo Jung-woo stayed up researching parallel dimension theories in this world. Though the internet was slower than in the other world, he was still able to search for information.

Since the first gate opened on January 1, 2000, countless theories had emerged.

By dawn, he found one theory that could explain his current situation.

“Professor Kim... I’ll go see him tomorrow.”

The university professor Seo Jung-woo met carried a handgun on his waist even on campus. The students were no different.

Seeing a professor he didn’t know required a consultation fee. That was common sense in this world.

Seo Jung-woo paid generously. The professor, in return, kindly explained his theory.

On his way back, Seo Jung-woo reflected on what he had learned.

“The theory that one dimension splits into two parallel dimensions at a specific moment...”

Whether that theory was true or not, it perfectly matched his experience.

“If this theory is correct, then this world and that world split into two on January 1, 2000—the day the monster invasion gate first opened.”

But Seo Sora was born years before that. According to the theory, the Seo Sora from the other world—the idol trainee and university student—was the same younger sister who had lived with him until December 31, 1999.

On January 1, 2000, when the world split into two, his younger sister had simply doubled.

“So that Seo Sora, the one who treats her brother like a nobody, is also my little sister. My long-lost sister, whom I finally met after 18 years.”

After meeting the professor, Seo Jung-woo packed his bags and took a bus far from home, to a location near his house in the other world.

Seo Sora asked,

“Are you sure about these coordinates?”

“Absolutely. In the other world, there was no one here.”

When crossing dimensions, one suddenly appears in an empty space.

In this world, if someone suddenly appeared, people would just assume they were a teleporter. That wouldn’t be a problem.

But in the other world, a person appearing out of nowhere would cause a panic.

That’s why he had secured a safe location before returning.

In the other world, this location contained an abandoned building where construction had been halted. It had been left untouched for years, meaning no one came near it.

Seo Jung-woo opened his armored suitcase, which looked like a travel bag, and checked its contents again. Inside, it was packed with weapons—short submachine guns, disassembled automatic rifles, handguns, ammunition, grenades, and even explosives.

Seo Sora sighed regretfully.

“It’d be nice if you could take one more armored case.”

“Dragging around two of these would be too suspicious.”

“Oppa, be careful.”

“That world is so safe that I won’t be in any danger at all.”

Seo Jung-woo grinned and then lifted the case with both hands.

To teleport with an object, one had to either wear it or hold it. That was common sense.

Most skills had slight variations depending on the user. Teleportation skills also had minor differences, but they all shared one rule—no teleportation could transport another person.

“I’ll be back.”

He activated his skill.

In an instant, his surroundings shifted.

What appeared before him was the gray concrete wall of the abandoned building.

A gust of wind whirled around him.

“I made it back.”

On the gray concrete wall, he saw the markings he had left. Proof that he had returned to the correct world, not just a similar one.

He let out a deep sigh of relief.

“Whew... I was worried for a moment, but the dimensional coordinates are fixed. Now, let’s check the time coordinates.”

Dragging his suitcase, he walked outside and asked a passerby for the current date and time.

It was the exact moment he had left.

“No matter how much time passes in the other world, the time coordinate here remains unchanged. The only variable is the three-dimensional space coordinate.”

The test was complete.

There were no more unknown factors when traveling between the two worlds.

The connection between the two dimensions was now stabilized.