Just as Tsunade had said, work that was completely impossible for Leo was, for her, no more than a casual stroll after dinner.
More importantly, she did it with absurd ease.
A single jump covered seven or eight meters in distance and five or six meters in height. With a bit of effort, she could even leap straight from the bottom of the ravine up onto the rooftop. Watching this, Leo was left completely dumbfounded.
He knew Tsunade was a ninja, and he'd seen what ninja could do back when he watched anime, but seeing it in person was something else entirely. Only then did he truly understand just how outrageous and shocking it really was.
Honestly, if Tsunade hadn't personally admitted that blades could still cut her skin and that her defense against piercing attacks wasn't great, Leo would have thought she could audition for a female version of Superman: Man of Steel.
Scenes seen in animation and scenes witnessed in real life were two entirely different experiences.
He was absolutely certain that if it weren't for her hemophobia, Tsunade wouldn't need to fear the zombie horde at all. Even standing alone on a vast open plain, she wouldn't be in any danger whatsoever.
Finally, by the afternoon, after four or five failed attempts, they managed to construct a relatively safe structure.
"Hm… the rules of this world really are strange. Still, this is about the limit of what we can do for now."
Tsunade shrugged helplessly as she looked at the small cube in front of them, roughly five meters by five meters. After countless experiments, cautious adjustments, and repeated testing to ensure that no activity inside would cause a collapse, they had finally settled on this design.
The structure had no door. When the time came, they planned to seal the entrance with two steel blocks and lock everything in place using system blocks.
Around the walls were specially designed firing and ventilation windows, formed by reshaped steel frames. These would allow Leo and Kelly to continuously clear zombies from inside. These openings were also meant to be sealed with real steel blocks later, since only that could guarantee absolute safety.
"I still think you're a bit too scared of those zombies," Kelly said, looking at the house suspended against the wall and nodding. "But I've got to admit, this thing does look impressive."
She then pointed at the gap between the pillars and the invincible wall.
"Even after all those tests, it still feels like it could fall at any moment."
"As long as we don't randomly add blocks anymore, and the steel plates don't get punched through, it should be fine," Leo replied. "And besides, we have a backup plan."
He pointed to the untouched soil beneath their feet. Tsunade was currently embedding materialized steel plates into the soil below with her fists. Hidden inside that earth mound was a tunnel and a concealed chamber they had dug earlier. If things really went south, they could retreat through that passage to the underground shelter.
The reason they hadn't chosen that plan from the start was simple.
They didn't have enough steel frames.
If they used all of them to build an underground fortress, Leo was worried that the endless zombies would eventually dig through the foundation. Once that happened, the entire structure would collapse instantly.
So it was better to prepare two options.
During this time, Kelly also tried repairing the cement mixer. In the end, she could only spread her hands helplessly and admit she'd talked big earlier.
There was no motor inside it at all. Even she couldn't work miracles without that.
"Next comes trap construction," Leo said, looking at the vast, uneven pit before them. He took a deep breath and pulled out a large pile of gunpowder.
He first placed wooden blocks on the ground to act as supports, then materialized empty cans, filled them with nails, packed them with gunpowder, and embedded them into both the cans and the wooden blocks before arranging everything together.
What was even more insane was that he spread nearly half a meter of gunpowder across a large stretch of land, then covered it with wooden planks. His plan was simple: lift the floorboards later. Even if it didn't explode, the wood would at least ignite.
While doing this, he constantly crafted wooden spike traps in his inventory—several sharpened logs bound together like anti-cavalry obstacles—and fixed them into the ground, forming multiple defensive lines throughout the canyon.
"This guy's got a bit of a persecution complex, doesn't he…" Kelly muttered, twitching at the corner of her eye as she watched Leo work. "Anyone who wandered in here without knowing would be absolutely doomed."
"Let him be," Tsunade replied calmly as she reinforced the lower escape route with steel plates and partitions. "We've already mined almost everything here anyway. Once this is done, we won't really be staying here much."
She didn't think the zombies were that threatening to begin with.
Time passed as Leo obsessively laid traps. After lunch, he materialized wooden boards and built three beds and several partitions inside the steel house for the three of them. He also carried two buckets of water inside, then moved everything from their old wooden shack to the area beside the steel house.
At Leo's insistence, Tsunade and Kelly helped set up additional defensive structures and placed flammable materials in strategic locations, so Kelly could ignite them with gunfire if needed.
Most critically, while the two women were cooking, Leo went completely overboard and dug away the only remaining path leading outside, fully cutting off any access for zombies.
After all, with system blocks, they could easily build a new path whenever they wanted.
Tsunade and Kelly only pursed their lips at this and didn't comment, treating it as Leo being overly paranoid. Once they finished their work, they went to wash up, then used the money Leo had given them to buy a large amount of food and beer, planning to throw a small feast.
Leo didn't mind. He continued laying gunpowder until nightfall, then stepped on system blocks to return to the steel house and eat with them.
Lying on his soft bed, Leo gazed at the starry sky beyond the window, feeling an unprecedented sense of peace. Even though a thirty-meter-deep abyss lay beneath them, he had never felt this happy before.
"There's still tomorrow," he thought. "I can check for missions at places like police stations. In the U.S., police stations should have heavy firepower, right? And the emergency underground shelter can still be improved…"
Holding onto hope for the future, he slowly drifted into sleep.
Then, at the exact moment the clock struck midnight—
Yellow sand began to howl outside.