The detachable electric motors mounted on inflatable boats had tremendous advantages.

Unlike internal combustion engines, they required no ignition and generated torque instantly. Their structure was simple, allowing smooth continuous control from low to high speed.

They were also extremely quiet, and their top speed could reach twenty knots—around thirty-seven kilometers per hour—which was fairly fast.

But that didn’t mean they had no drawbacks.

No—

the biggest weakness of electric motors completely overshadowed all those advantages, which was why even before the apocalypse, boats using them had been rare.

The problem was battery life.

At most, they could only operate for three to four hours.

And that wasn’t at top speed either.

That was cruising at only fifty to seventy percent output.

***

“...So with the remaining battery, reaching the Ara Waterway is probably going to be difficult.”

Even though it was a premium German model costing four million won—unmatched in durability and noise reduction—there was no helping it.

In fact, the only reason they still had nearly seventy percent battery remaining was because this particular model used a built-in premium lithium system.

“Then what do we do?”

“We stop midway, recharge once, then continue. We need at least fifty percent battery before entering the Gyeongin Ara Waterway if we want to follow Gulpo Stream all the way to Bucheon.”

That had been Junho’s plan from the start.

Enter the Ara Waterway with the boat, then follow Gulpo Stream down toward Sang-dong in Bucheon.

From there, the straight-line distance to Chunui Mountain—where the Bucheon house was located—was only about 2.5 kilometers.

Of course, this was Bucheon, one of the most densely populated cities in the country.

Countless apartment complexes and residential areas were packed together there, meaning there could easily be tens of thousands of zombies.

Possibly over a hundred thousand.

But considering the distance from Gimpo near the lower Han River to that point exceeded ten kilometers, it was still worth attempting.

“I see. Then where are you thinking?”

At Yoon Seolhee’s question, Junho opened the old satellite map data he had downloaded sector by sector before the apocalypse and tapped a point along the Han River.

“Here.”

“Sangam...?”

“More specifically, Nanji Hangang Park.”

There were no large residential areas like apartment complexes within nearly a one-kilometer radius, making it ideal for stopping near the riverbank and charging for about a day.

“Wouldn’t someplace like Nodeul Island or Bamseom be better? They’re in the middle of the river.”

Kim Jimin suddenly cut in.

But Junho only smiled bitterly and shook his head.

“That would make sense. But it probably won’t work.”

“Huh? Why not?”

“You’ll understand once we get there.”

Quietly steering the tiller handle of the electric motor, Junho answered calmly.

“...?”

The two remained curious, but they would soon understand once they reached Nodeul Island.

So both of them stayed low inside the boat and kept watching ahead.

***

Wheeeee—

Changing direction repeatedly with the current, the boat maintained a cruising speed of ten kilometers per hour as it traveled down the Han River.

After passing Banpo Bridge, now completely submerged beneath the raised water level, the boat moved beyond Dongjak Bridge and approached Hangang Bridge, leaving Nodeul Island roughly one kilometer ahead.

“.......”

The two alternated between the KP9 scopes and the drone footage, carefully observing the island growing closer.

Then finally, the wide-angle camera of the drone circling overhead captured the full view of Nodeul Island across a roughly three-hundred-meter radius.

The moment they saw it, both of them inhaled sharply.

“...!?”

As the two widened their eyes in shock, Junho’s voice reached them.

“Just as expected. Looks like Nodeul Island has already been occupied by zombies. And from the look of it, it’s Alpha territory.”

With the river level risen high enough to flood all sections near the water, Nodeul Island had lost twenty to thirty percent of its total land area.

And the place was horrifying.

Most of the small wooded areas showed only traces of fire damage.

Abandoned vehicles and partially skeletonized corpses littered the center of the island where Hangang Bridge crossed through.

And on the rooftop and exterior of a nearby building that appeared to be part of the parking area—as well as across the bridge itself—stood dozens, even hundreds, of zombies.

“What the hell are they doing?”

Kim Jimin swallowed hard while staring at the grotesque sight of zombies lined up in orderly rows outside and across the bridge.

Junho spoke quietly.

“You see the same thing on the opposite side too, right? Toward the Live House area and the bridge leading toward Ichon-dong.”

“.......”

Kim Jimin nodded with a pale expression.

Junho continued.

“They’re standing watch. Looking for survivor boats passing through.”

“...!”

Just as Kim Jimin’s eyes widened—

Junho, who had been closely watching the tablet, spoke quickly.

“Several boats are entering from the Gangbyeonbuk-ro side toward Ichon-dong.”

“What...!?”

Startled, the two looked at the drone feed.

Sure enough, several small boats were slowly moving upriver.

“Ar-aren’t those duck boats?”

“Yeah. Anyway, we’re heading the opposite direction.”

Even while Junho changed course, neither of them could take their eyes off the screen.

They had seen videos before—variety shows and YouTube clips of people crossing the Han River in duck boats.

But these four duck boats weren’t crossing the river.

They were trying to move upstream.

And because duck boats relied on human-powered pedals, there was no way they could move quickly.

Still, despite their painfully slow pace—barely faster than walking—the four boats continued struggling against the current somehow.

Watching their desperate effort made both of them instinctively want to cheer for them.

“Tch. That’s not going to work.”

“...?”

Junho clicked his tongue while staring bitterly at the screen.

“You’ll see if you keep watching. Anyway, don’t move from now on.”

“Yes.”

Lying under the camouflage tarp with only their gun barrels sticking out, the two remained completely motionless while watching the tablet screen.

Soon, their boat slowly passed beneath Hangang Bridge.

Just thinking about the hundreds of zombies directly overhead—zombies that would immediately jump down the instant they noticed humans below—sent chills down their spines.

“...Ah.”

Then suddenly, Yoon Seolhee realized something and quickly checked the screen again.

“Oh no....”

She immediately understood that her suspicion was about to become reality.

The zombies lined up across the bridge had noticed the duck boats.

Even though they moved slowly, they were still moving.

“N-no way...?”

Kim Jimin realized it a second later and muttered with a trembling voice.

Junho answered quietly.

“Yes. Exactly that.”

His eyes hardened.

“Because those aren’t normal zombies. They’re under an Alpha’s control.”

Zombies naturally reacted to movement within visual range.

But unless it was prey—actual humans—their interest usually faded quickly.

However—

“That only applies to ordinary zombies. Ones controlled by an Alpha are different.”

***

The Alpha occupying Nodeul Island had almost certainly learned what duck boats were.

No—

it probably recognized every kind of object moving across the river and understood that humans were riding inside them.

So while fast-moving motorboats or jet skis might escape notice—

slow duck boats were another story entirely.

“Ah!”

“Hhk...!?”

Yoon Seolhee and Kim Jimin’s eyes widened.

The zombies lined up across the bridge toward Ichon-dong suddenly began sprinting together toward one point.

And that point was directly beneath the bridge—

where the duck boats were about to pass.

The moment the four boats entered underneath—

dozens of zombies leaped down.

Some crashed directly onto the duck boat roofs or into the water beside them.

The impact severely damaged several boats.

One even flipped over completely.

But ironically, the overturned boat was the lucky one.

Because despite impacts strong enough to punch through the roofs, the zombies survived.

And they succeeded in biting the people inside.

“......!”

No sound reached them.

But somehow that only made it more horrific.

Blood and flesh spraying everywhere.

Panicked survivors jumping into the Han River.

Zombies greedily tearing apart living humans regardless of whether the boats sank beneath them.

“Kh...!”

“Fuck... fucking bastards.”

Watching fellow humans become zombie prey in real time from so close away filled both of them with indescribable emotions.

Then Kim Jimin, staring at the screen with bloodshot eyes, suddenly thought of something.

“But wait. Those sons of bitches are acting like that because the Alpha’s controlling them, right?”

“Yes.”

“This is seriously weird. What does the Alpha even gain from that? It can’t eat those people itself. The zombies can’t swim over and drag them back either.”

He was right.

The zombies couldn’t swim.

They couldn’t operate duck boats either.

That was simply the end of it.

Meaning the Alpha gained absolutely nothing.

But Junho—

a regressor who had already witnessed scenes like this many times—

knew the answer.

“Because it’s fun.”

“...!?”

The unexpected answer left both of them speechless.

“Think of cats. Cats don’t always hunt mice or birds because they want to eat them. Most of the time they kill them for fun.”

“Ah....”

“And large predators are the same. They don’t tolerate other creatures entering their territory. Just like elephants or hippos don’t attack humans because they want to eat them.”

“This is insane....”

“No.”

Junho returned the drone toward the airspace ahead of the boat, his gaze far colder and more furious than either of theirs.

“It’s not insanity.”

His voice hardened.

“I said this before. Alphas should be treated as an entirely new species. To them, this behavior is perfectly natural.”

His eyes sharpened with murderous resolve.

“That’s why we need to study those fucking things calmly and objectively. Only then will we eventually be able to kill them all and win.”

That was precisely why he had built the shelter.

***

Leaving behind the horrific deaths near Nodeul Island, the boat carrying the three of them continued down the Han River.

And just as Junho had said, Yoon Seolhee and Kim Jimin soon confirmed that the half-submerged Bamseom wasn’t much different from Nodeul Island.

Yeouido, however, was another story.

Centered around the National Assembly building, parts of Yeouido had already been fortified.

The roads connecting Seogang Bridge, National Assembly Boulevard, and the intersections leading toward Yeongdeungpo had all been blocked off.

Meanwhile, the lawns around the National Assembly and nearby parks clearly showed signs of cultivation, including greenhouses and farming plots.

There were also numerous solar panels installed throughout the area.

'At least two or three hundred people. Maybe over five hundred.'

And the survivors based around the National Assembly appeared to control multiple buildings across the river as well.

More importantly, they were surviving in almost the exact same way Gahyeon-ri had.

Barricades made from abandoned vehicles and furniture had been erected, then secondary walls built every hundred meters or so to create observation points.

“People really do think alike.”

The two stared in fascination.

More than anything, after witnessing the horrifying deaths earlier, simply seeing other humans somehow continuing to survive made them feel slightly better.

Meanwhile, the boat kept moving slowly.

Eventually, around noon, they finally reached their destination near Nanji Hangang Park.

But even there, most of the riverbank had been flooded due to the increased water level.

Compared to the original map, nearly fifty meters of shoreline had disappeared underwater.

In the end, they had no choice but to dock beneath Gayang Bridge near Gangbyeonbuk-ro.

And there was another reason they couldn’t stop deeper inside Nanji Hangang Park.

First—

the electric motor battery was nearly depleted.

“And from now on, we should probably avoid riverside parks and campgrounds. I didn’t expect survivors to be living in all of them....”

Probably because water was the single most important necessity for survival, huge numbers of survivors crowded both Nanji Campground and World Cup Park across Gangbyeonbuk-ro.

And in the apocalypse, survivors other than your own group were—

“We really need to be careful. This place is basically a forest now, and it’s over five hundred meters away, but this might still be their territory.”

From far away through drones or surveillance cameras, they looked like fellow humans deserving sympathy.

But up close, they could turn into looters just as dangerous as zombies at any moment.

And after nightfall—

Junho’s concerns became reality.