Uchiha Nagi pointed to the sword on the ground. "See? Except for the extreme southern and northern regions, it's basically the same everywhere under the heavens. The sun always travels from east to west."
"So, we'll make a mark at the tip of the shadow."
With that, Uchiha Nagi took another kunai and scratched a mark on the ground at the end of the longsword's shadow.
"Then, we wait a little while, and the shadow will move to the other side…"
After a short time, as the sun moved, the sword's shadow began to shift. It moved to a different spot, and Nagi once again used the kunai to mark the new position of the shadow's tip.
Yukihime, ever the bookworm, understood instantly. "I get it! The sun rises in the east, so the first mark you made is west. Then the sun moves towards the west, so the sunlight shines from the other direction, making the second mark you made the east, right?"
Uchiha Nagi nodded. "Except for about an hour around noon when the sun is directly above you, you can use this method to tell the direction at any other time."
"See, once you've distinguished east and west, north and south become easy to identify."
Yukihime raised her hand and asked, "But what if I don't have a longsword? What can I use to figure out the direction then?"
Uchiha Nagi looked at her, a little speechless. "…"
Little Kimimaro, however, smiled. "You can use a kunai, or a branch from the roadside. Or even your own shadow. As long as there's a shadow, you can tell the direction, right, sensei?"
Uchiha Nagi smiled and nodded. "A teachable child. This is one way to tell direction during the day in the desert. At night, you can navigate by the stars."
"At the same time, in primeval forests or in the extreme north and south, you have to use different methods. Different geographical locations mean you can't generalize."
Like a curious child, Yukihime asked, "Why is it different?"
"Because the Earth is round. So in different locations, the way the sun shines and the magnetic fields are different. The methods used to determine direction must naturally be different as well."
"Huh? How do you know the Earth is round? Then why don't we fall off?" Yukihime pressed on with another question.
"…"
Uchiha Nagi suddenly didn't want to explain anymore. To explain the first thing, he'd have to explain countless others. How long would that take?
"Sensei says it's round, so it's round."
Fortunately, he had a little follower in Kimimaro who worshipped him blindly and didn't ask so many 'whys.' Otherwise, Uchiha Nagi would have gone mad.
Uchiha Nagi looked up at the sun. Kimimaro and Yukihime were extremely thirsty, so he once again opened a storage scroll and took out a few water flasks, handing them to the two of them.
"Don't let the sun shine directly on your skin. Even if it's hot wrapped up in clothes, you must cover up. That will reduce your body's heat absorption and decrease water loss."
Yukihime gulped down a whole flask of water in one go, her small stomach bulging, but she still felt incredibly thirsty.
"So that's how it is. No wonder I felt so thirsty no matter how much water I drank."
Hearing this, Yukihime immediately used a white headscarf to wrap her head tightly. Kimimaro followed her example and covered himself as well. Although his constitution was strong, it didn't mean he was immune to the heat.
After drinking water and resting for a while, the three continued on their way. It had been three or four days since they had escaped the daimyo's city. For a ninja, traveling a hundred kilometers a day was not a problem. If it weren't for Yukihime slowing them down, Uchiha Nagi would have been much faster.
But after leaving the oasis and entering the boundless desert of the Land of Wind, their pace slowed. They had to stop from time to time to compare their position with the map and determine their direction.
"Hey, sensei, look! There seems to be some kind of building over there," the sharp-eyed Kimimaro said, spotting the ruins of a structure in the distance.
"Mm, let's go over. That might be our destination."
The three of them walked into the architectural ruins amidst a vast wasteland. The wind and sand were fierce here, and many of the buildings were half-buried. It was no wonder that many guides today no longer knew the way to the Land of Roran.
"Roran…" Uchiha Nagi muttered to himself, looking at the ruins.
"Right, why did you have to come to Roran? It's a small, ruined country. Is there some kind of treasure hidden here?" Yukihime asked curiously.
"Mm, I came to see. I heard there's a treasure here…"
Although Kimimaro didn't ask, his eyes also held a hint of curiosity. They had traveled all the way to the Land of Wind, snuck into the daimyo's city to steal a map, and gone through so much trouble…
It was because the Ryumyaku was here—a unique energy that could be used by ninja.
Uchiha Nagi didn't answer, but instead tried to recall the memories hidden deep in his mind. There was a guy named Mukade, who had schemed for a full six years, calculating every move, before he successfully claimed the Ryumyaku for his own. He then turned the Ryumyaku into a chakra battery similar to a Tailed Beast, with an inexhaustible supply of energy. He had completely depleted Crown Prince Naruto's blue bar—of course, the Naruto of that time had not yet learned senjutsu or mastered the complete Nine-Tails Mode.
Afterward, Mukade, combined with his Puppet Technique, could regenerate from any damage. Although his combat power wasn't strong, as long as his 'mana' wasn't depleted, he was immortal and indestructible. He had nearly worn out both Naruto and Minato.
But this was enough to prove the terrifyingly immense power of the Ryumyaku. Nagi wanted to see if the Ryumyaku, since it could be used by people, could be sealed into a human body like a Tailed Beast.
His own chakra reserves were enormous, but after his battle with Orochimaru that night, he knew he still had a ways to go to match Orochimaru's 'mana pool.' And Jiraiya and Tsunade had even more. Obito, with half his body made of White Zetsu cells, and Nagato—their chakra reserves were probably even more terrifyingly vast.
Who would refuse a larger mana pool?
"Water Style: Water Dragon Bullet Technique!"
Several jets of water instantly converged into a small pool.
He tried casting a water jutsu and found that it wasn't as strenuous as it was in the deeper desert, where it required several times more chakra. This proved that there was more moisture in the air here, and likely an underground river.
"You two wait here. I'm going to scout around."
Uchiha Nagi pointed to the buildings. Although the ruins were ancient, they could still provide some shade from the scorching sun.
Yukihime, so hot that she was sticking her tongue out without any regard for her image, immediately ran inside.
"Okay, sensei." Kimimaro nodded and also went in to take shelter from the sun.
Nagi then leaped away, sending out several clones to survey the surrounding terrain. As he was inspecting the central area of the ruins, he suddenly felt a strong wave of hostility and killing intent.
Killing intent means an enemy. He slowly drew his Nichirin Blade and a kunai.
Swoosh—
Before the opponent could react, several kunai with exploding tags attached were already on their way, probing the enemy's hiding place.
BOOM!