After taking over the snake uncle's foundation, Sasuke came to surrender on his own initiative.

Sasuke shook off Kakashi's hand, his eyes full of vigilance, "Why did you do this? What conspiracy is hidden behind this?" Kakashi sighed helplessly, "Sasuke, there are some things that I can't tell you now. But I can guarantee that no matter what the result is, it is the best arrangement for you." Sasuke snorted coldly, "I don't need your so-called arrangement, I only believe in my own strength." As he said, Sasuke opened his Sharingan, ready to deal with emergencies at any time. Kakashi shook his head, "Sasuke, calm down. Going to Orochimaru may make you stronger, but it is also full of dangers; and if you are taken to the Land of Demons, you may be able to unlock some secrets about your eyes." Sasuke gritted his teeth, "Anyway, I won't let anyone manipulate me." At this moment, a strong chakra fluctuation suddenly surged around, as if a mysterious person was approaching. Kakashi's face changed, and he whispered, "It seems that we are being targeted. Let's leave here first." Sasuke glanced at Kakashi, and finally nodded, and the two quickly fled into the distance.

The two had just escaped a short distance when they were blocked by a group of black-robed people. The leader slowly raised his head, revealing a pair of cold eyes, "Kakashi, do you think you can easily escape with Uchiha Sasuke?" Kakashi clenched the kunai in his hand, "So you are from the Root Organization, what do you want to do?" The black-robed man sneered, "Sasuke is an important combat resource and must not fall into the hands of others." A trace of anger flashed in Sasuke's eyes, "You guys also want to use me?" After that, Sasuke took the lead in launching an attack, and the Sharingan released a powerful illusion and rushed towards the black-robed crowd. Kakashi was not to be outdone, and cooperated with Sasuke to fight. However, the people of the Root Organization were well-trained, and the two sides were deadlocked for a while. Suddenly, a strange bird cry came from the sky, and a huge eagle swooped down. It turned out to be a summoned beast summoned by Sasuke, and it swooped down on the black-robed man. Taking this opportunity, Kakashi pulled Sasuke onto the eagle's back, "Let's go!" As the giant eagle flapped its wings and flew high, the attacks of the black-robed man fell through. Sasuke looked at the gradually shrinking figure below, and secretly vowed in his heart that he must improve his strength as soon as possible to escape the fate of being coveted by various forces.

Sasuke and Kakashi flew on the giant eagle for a long time, and only landed when they were sure that the Root Organization had not chased them. At this time, Sasuke said to Kakashi with a serious face: "I know that my strength is not enough, but I don't want to be involved in an inexplicable struggle again. I want to find the way of practice that truly belongs to me." Kakashi thought for a moment and responded: "Sasuke, I actually know a place. It is said that there is a special ninjutsu secret book there that can greatly improve the ability, but it also comes with huge risks." Sasuke did not hesitate to say that he was willing to give it a try. So they headed towards the place Kakashi mentioned. On the way, they passed a foggy forest filled with a strange atmosphere. When they carefully crossed the forest, they found that Kabuto was studying something in an open space. Sasuke was about to rush up to question him, but Kakashi stopped him in time and whispered: "Let's see what he is doing first." Kabuto extracted a substance from a corpse and put it into a container, with a weird smile on his face. Sasuke couldn't contain his anger, and rushed out despite Kakashi's obstruction, shouting, "Kabuto, what bad things are you doing here!" Kabuto looked up and saw Sasuke and Kakashi. A trace of panic flashed across his face, and then he calmed down. A new conflict was about to break out.

Kabuto quickly put away his panic and sneered, "Sasuke-kun, I'm just doing some medical research. But why are you here?" Sasuke glared at him, "Humph, who would believe your words? You must have bad intentions." Kakashi stepped forward and stared at Kabuto, "Kabuto, we have no intention of conflicting with you, but if you really do something that harms the village or others, we will not stand idly by." Kabuto shrugged, "I left Konoha Village a long time ago and am not under your control. As for harming others, I am just exploring the mysteries of life." Sasuke clenched his fists, "What do you mean by exploration is playing with corpses?" Kabuto was about to refute when suddenly a low roar sounded around. A group of monsters that looked like wolfhounds, but were huge in size and had dim eyes, rushed out of the mist. Kabuto's face changed, "Damn it, my movement attracted the dark beasts raised by the Hidden Mist Village." Kakashi looked at Sasuke, "It seems that we have to solve the trouble in front of us first." Sasuke opened his Sharingan, and the three were forced to stand on the same front temporarily to fight against the dark beasts together. Sasuke swiftly shuttled between the dark beasts, Kakashi used Raikiri to attack continuously, and Kabuto threw various potions to interfere with the dark beasts' actions. After a fierce battle, the dark beasts gradually retreated. Kabuto wiped the sweat from his forehead, turned around and left silently. Sasuke and Kakashi looked at each other and continued on the road to their destination.

Sasuke and Kakashi walked along the winding path and soon came to an ancient cave. The cave entrance exuded cold air and there were faint fluctuations of restrictions. Kakashi said solemnly: "This is where the ninjutsu secret book is, but the restrictions are very strong." Sasuke took a deep breath and said, "I can't care so much."

The two worked together to break the ban and enter the cave. The walls of the cave were engraved with strange runes, and deep inside there was a scroll that was glimmering. Just as Sasuke reached out to take it, a teleportation circle suddenly appeared under his feet. Sasuke was startled, and Kakashi hurriedly shouted: "Be careful!"

Instantly, they were transported to a strange space. Surrounded by clouds and mist, a majestic voice sounded: "Outsiders, if you want to get the secret book, you must pass the test." Before the voice fell, countless phantom ninjas appeared and attacked. Sasuke and Kakashi fought side by side. Sasuke's Sharingan kept seeing through the flaws of the phantoms, and Kakashi used Raikiri to launch a powerful attack.

Finally, the phantoms all dissipated. The voice came again: "You have passed." The secret book flew to Sasuke. Sasuke looked at the secret book, his heart full of excitement, he knew that he was one step closer to becoming stronger and could better control his own destiny.

Sasuke could not wait to open the secret book, but found that the handwriting on it was blurred, as if it was sealed by a mysterious force. Kakashi took a closer look and frowned, "This may not be that simple. Maybe a specific method of unlocking the seal is needed." Sasuke reluctantly tried to inject chakra, and suddenly the secret book emitted a strong light, covering Sasuke. Sasuke felt his consciousness being pulled into a dark space, and all kinds of strange whispers echoed around him. Kakashi anxiously called Sasuke's name, but could not reach the light curtain.

In the dark space, Sasuke met a soul who claimed to be the guardian of the secret book. The guardian told him that only those who have a pure heart of revenge and can endure great pain can decipher this secret book. Sasuke firmly stated that he was willing to accept any test. The guardian waved his hands, and Sasuke immediately felt a piercing pain, as if every cell in his body was burning. But Sasuke gritted his teeth, thinking of his family's hatred, the fire of revenge in his heart became even stronger.

Outside, Kakashi noticed that Sasuke's chakra fluctuations were abnormally violent. When he was about to break the seal by force, Sasuke suddenly broke through the light curtain, and the words on the secret book appeared clearly. Sasuke successfully took a key step towards becoming stronger.