After finishing their meal, Leo went into the nearby forest and chopped down several trees, gathering enough wood to build wooden frames around the RV. Since he already knew that the stone axe could upgrade these structures, he quickly figured out how the upgrading worked.
It was simply a right-click.
Upgrading a wooden frame required eight pieces of wood, and once upgraded, the frame's durability jumped to 500. Leo then tried upgrading it further and discovered that the next upgrade required cobblestone. Cobblestone, in turn, required clay and stone.
After thinking for a moment, Leo immediately crafted a stone shovel and experimentally slammed it into the ground. The next instant, a durability value appeared, along with a notification that clay had been added to his inventory. After digging a few more times, a large pit quickly formed in the ground.
Looking at the pit—already about a meter deep—Leo scratched his head.
"Wow… that's pretty 'user-friendly.'"
He had only dug three times, yet the hole was already this deep. To be honest, even he was a bit stunned. But this confirmed something important: surviving in this world really wasn't that hard, as long as you didn't do anything stupid.
Leo crafted ten pieces of cobblestone—not because he didn't want to make more, but because he had run out of small stones. When he upgraded a wooden frame with 500 durability, the structure instantly transformed into a brick wall made entirely of masonry.
He tapped it with his stone axe, and a number appeared.
1457 / 1500.
"The defense increased too!"
Leo was delighted. But when he tried to upgrade it further, a material shortage warning popped up, telling him he needed cement for the next upgrade.
That gave Leo a headache.
Cement wasn't like other materials—it required a cement mixer to produce, and that required a workbench. There was no way around it, which left Leo feeling quite helpless.
"Looks like tomorrow I really am becoming a mining youth."
Glancing at the sky, Leo gave up on continuing work for the night. Nearby, Erina had already put out the campfire and was helping him upgrade the remaining wooden frames to wooden plates.
Yes—they had completely surrounded the RV with walls and even installed a wooden door crafted through the system to allow easy entry and exit.
After all, once a frame was upgraded, it couldn't be retrieved anymore.
"Time to sleep."
Stretching lazily, the two of them went inside.
As before, they each slept in separate rooms. Erina slept soundly, but Leo did not.
The effects of that meal hadn't been fully burned away by labor. If anything, lying down made the heat in his body more noticeable.
Though he still had a mild fever, his physical reaction was unavoidable.
"Damn it…"
Leo sat up in the middle of the night, covering his face.
He couldn't sleep at all.
The fire inside him kept flaring up, leaving him at a loss. And worse, he had a target—someone he could do something with without any moral issue.
Not Erina. He had no intention of doing anything with her yet. He planned to let things develop naturally over time.
The one on his mind was the female trader.
That massive chest, the full hips and legs—physically, she was perfect. Her face couldn't compare to Erina's, but that wasn't the point.
The key was that she didn't require emotional involvement.
Erina, for all her beauty and growing emotional reliance on him, was a partner—a comrade surviving alongside him in this world, not an object.
"Am I really going to break my own bottom line?"
Leo looked at his hands. Even though he'd washed them with water, he could still smell zombie blood. Who knew whether doing something like that would get him infected again?
If he really got infected in such a ridiculous way, he wouldn't even know what to say.
Still, the restless desire was unbearable. Leo could only pull the blanket over his head.
What he didn't know was that, in the next room, Erina was also having trouble sleeping as she listened to his heavy breathing.
The human body is strange. After intense combat and strenuous activity, it naturally craves intimacy—especially after adrenaline-fueled situations that trigger primal instincts.
That's why physically active people often have stronger desires, while those who rarely move or take risks may barely feel them at all.
This night, Leo dreamed of many things—most of all, the feeling of kissing Erina, and the softness of the trader's chest in his hands.
When morning came, he cursed under his breath, then dragged himself up, still feeling drained, and went to inspect the wooden walls around the RV.
He placed a wooden frame in front of himself, jumped onto it, then suddenly thought of a classic trick used in Minecraft-like building games.
He jumped again, leaping about a meter high, and in midair placed a wooden frame beneath his feet.
In the next instant, he was standing on it.
"It actually works!"
Leo felt a surge of excitement. This opened up so many possibilities—climbing mountains, reaching places zombies couldn't touch, and more.
"That means getting onto the gas station roof might be even easier than I thought!"
With that thought, Leo walked along the wall, checking for zombies or wild animals.
Fortunately, there were none. Even the wall's durability hadn't dropped at all.
At that moment, Erina came out of the RV with the leftovers from last night. Leo jumped down from the wall and nodded to her.
"After breakfast, we'll head into town and scavenge useful stuff—mainly duct tape and anything that looks usable."
Erina didn't object. Having also slept poorly, she reheated the food while listening to Leo explain his new discovery.
When she heard about placing blocks in midair, her face lit up with excitement.
But just as they were about to eat, a shrill female scream suddenly rang out from outside—inhuman and piercing.
Leo and Erina immediately went on alert. Leo jumped onto the wall and looked toward the source of the sound.
Any hope of finding a survivor vanished instantly.
The screamer was a pale, battered zombie staggering toward them.
It looked almost exactly like Sadako from a horror movie. The moment Leo saw it, he knew it couldn't be alive.
It stared at him with greedy eyes and screamed again.
The next instant, loud crashes echoed from the nearby town—doors and windows shattering. Over a dozen zombies burst out of buildings and sprinted toward them.
Sprinted.
In broad daylight, these zombies were moving with the speed they should only have at night, charging toward them like Olympic sprinters.
"Damn it!"
Leo leapt down without hesitation. A stone spear appeared in his hand, and he pulled his axe from his inventory as he charged straight at the screaming zombie.
In just five seconds, he reached it. As it opened its mouth again, Leo drove the spear straight through its mouth, pinning it to the ground.
Then, gripping his axe with both hands, he buried it in the zombie's skull, ending it completely.
But the sprinting zombies didn't stop. They kept coming, now less than a hundred meters away.
Leo yanked his axe free and ran for the wall. By the time he reached it, the zombies were already within ten meters.
"Grab me!"
There was no time to place frames or open the gate. Erina was already kneeling atop the wall, reaching down.
Leo jumped, grabbed her hand, hooked the wall with his other arm, and with her help flipped himself up.
The next moment, the zombies slammed into the wall.
"Damn it… so there really are special zombies."
At least twelve of them. Leo's heart was pounding wildly. If he'd been knocked down, he would've been torn apart—not infected, but eaten alive.
After catching his breath, he heard claws scraping against wood. Looking down, he saw the zombies furiously scratching at the wall. Some even headed for the wooden gate.
The only saving grace was that they had slowed down again.
"At least there's some good news."
Leo took a deep breath, flipped back inside the wall, grabbed his axe, opened the wooden gate, and split the skull of a zombie clawing at it.
Blood sprayed everywhere. Leo stepped aside as Erina's axe fell, taking down another. Together, they alternated strikes, killing each zombie that tried to enter, then went outside the wall to finish off the rest.
When the last zombie fell, Leo collapsed onto the grass, gasping for air. Erina, still barely breathing hard, walked over, worry on her face.
From this angle, Leo could easily see her underwear and its outline.
He froze for two seconds. With adrenaline still high, dangerous thoughts crept in. To avoid doing something stupid, he immediately looked away, sat up, picked up his nicked axe, and stared toward the town.
"We need guns. And we need shifts. Until the RV is fixed, it's too dangerous. We need a proper base—watchtower included—and a rotation for guard duty."
If he'd had a gun and decent aim, this wouldn't have been so dangerous. That screamer could've been killed before it screamed a second time.
With a lookout on duty, it would've been even easier.
"I agree."
Erina nodded. His suggestions were completely reasonable.
After eating, they headed back into town. Leo stayed cautious—many buildings were still unexplored, and another screamer could appear at any moment.
Before coming, Leo had prepared.
Lacking feathers and archery skill, he skipped bows. But he discovered that spears could be thrown. So he packed a bunch of them.
If a screamer got blocked by other zombies—
He'd have Erina spear it.
Yes. He'd tested it. Even at throwing spears, Erina was more accurate and hit harder than him.
That realization hit Leo hard.
So while scavenging an unvisited house, watching Erina bend over and unconsciously cause an enticing sway, Leo couldn't help thinking:
"…Is Erina the real protagonist?"
And he?
Just the disposable middle-aged guy who dies to trigger the main character's growth?