Kirito and Eugeo are now second years at the Sword Mastery Academy and placed fifth and sixth in the top twelve. One day they are requested by their valets to help another valet who is being made to do embarrassing tasks. They break the Taboo Index and, consequently, are arrested by Alice, who is now an Integrity Knight, and sent to the Axiom Church prison. In prison, the two boys realize that they can break out but are intercepted by the Integrity Knight Eldrie Synthesis Thirty-one.
Chapter 5 - Seal of the Right Eye
Eugeo recalled the events that led to the current time, including his and Kirito's surprise of having received female valets. After Ronye Arabel and Tiese Shtolienen left the room with the bag of honey pies given to them by Kirito, Kirito asked Eugeo if he would like to practice. Eugeo informed him that they would soon have tests, and that Kirito should study for them. Admitting to this, Kirito decided to cram his studies, and asked Eugeo to get him some food from the cafeteria later. Eugeo decided to go to the Training Hall, but found that two students had also occupied it, Humbert Zizek and Raios Antinous, who had previously harassed Kirito and Eugeo for being commoners.
Eugeo decided to ignore them, despite their attempts to annoy him. He decided to strike a practice log, while considering the words of Kirito regarding the strength of one's sword. He claimed that the style Raios and Humbert use drew power half from their own strength, and half from their bottomless pride. After finishing his practice, Humbert mocked Eugeo's lack of form and offered to teach him a proper one. To his surprise, Eugeo accepted his lesson in the form of a practice match. After a struggle to overpower one another, Eugeo barely managed to disarm Humbert before Raios called the match a draw. Eugeo contemplated the strength he saw behind Humbert's sword, and wondered what he could use to put into his sword.
Days later, Kirito and Eugeo took their valets to the forest. While eating lunch they asked for their help, explaining that Humbert had been requesting strange things from Frenica Szeski, his valet and Ronye and Tiese's friend, to the point of making her cry all night long.
Eugeo decided to take action since he felt that it was his fault for fighting Humbert, and with Kirito, they visited Humbert and Raios' room to talk to them where they played dumb and acted as if they had not done anything bad. The next day Tiese entered Eugeo's room after she finished the cleaning and told him about her dad's intention of allowing her to enter the Swordmanship Academy to raise her family status and asked Eugeo to marry her if he did not win the Four Empires Tournament, to which Eugeo agreed.
The next day, while Kirito and Eugeo were in their room cleaning their swords, they noticed that Tiese and Ronye had yet to arrive as they normally do. Kirito decided to hurry to the trainee dorms by rushing out the window, and had Eugeo wait in the room in case they show up. After waiting for some time, Humbert's valet, whom he had humiliated before, came to Eugeo's room. She thanked and apologized to him, telling him that Tiese and Ronie had headed to Humbert and Raios' room earlier that day. Eugeo asked Frenica to stay there in case Kirito returned, and hurried to Humbert and Raios' room. He realized he had taken his sword, but decided there was no time to go back and leave it.
Upon arriving, he was greeted by Raios and Humbert who seemed drunk. It was not long before they revealed Tiese and Ronye to him, tied and bound in their bed. As it turned out, they knew Frenica was friends with Tiese and Ronye, so they expected Frenica to cry to her friends, and them in turn to tell Kirito and Eugeo about her ordeal. As they expected, after Kirito and Eugeo's confrontation with Humbert had no effect, Tiese and Ronye went to confront them and lost their composure. This was what they wanted, so that they could use their rights as upper Nobles to punish the lower nobles, to apply punishment through raping them. They waited for Eugeo to arrive, so that he could watch in horror.
Eugeo fought with his conscience and his inability to go against the Taboo Index, while the pain in his right eye increased as he watched the elites' actions. With Tiese's last scream before they were just about to commit the deed, Eugeo finally built up the willpower to go against the rules and swung his sword at the two. Raios was fast enough to move out of the way, but Humbert's left arm was severed. As a result, Eugeo's right eye was blown away, and all he could see through that eye was a red "Error" message in English. Raios was amused that Eugeo broke a Taboo, and managed to calm Humbert, who was panicking without his arm. He told him to use two of the ropes, which held Tiese and Ronye down, to tie up his wound.
Eugeo was in shock and collapsed after swinging his sword and losing his eye. Raios grabbed his sword, and told Eugeo that, as a criminal, he was to be killed. Before Raios could strike, Kirito came in and stopped the blow. Raios told Kirito that Eugeo was a criminal who severed Humbert's arm, and Kirito exclaimed that he did not care about taboos or the nobles' authority to judge. The two fought, with the result being both of Raios' arms getting severed, sword in hand. Raios paniced as his Life drained away, but died before Kirito could to save him. Humbert, in fear and panic, ran out of the room, calling the duo murderers and monsters.
The two untied the girls and comforted them, before a face appeared from what looked like a Stacia Window and muttered something about their location, but they were unable to understand it.
The next day, Kirito and Eugeo were in the underground discipline chamber, where Dormitory Supervisor Azurica visited them. She treated Eugeo's eye and told them words of farewell before taking them to the practice arena, where their escort was waiting to take them to the Central Cathedral. On the way they saw a dragon, so Eugeo knew that their escort was actually an Integrity Knight.
With resolution, Kirito entered the arena, followed by Eugeo, and they presented themselves to the Integrity Knight who presented herself as Alice Synthesis Thirty. Eugeo recognized his childhood friend and called for her, but when he tried to touch her, she removed her scabbard from her sword belt, using it to hit Eugeo across the cheek, and warned that if he tried to touch her again, she would sever his hand. Kirito made Eugeo regain his composure and both were taken to the plaza where the dragon was waiting.
Alice binds them with chains and leather belts, restraining their moves. In that moment Tiese and Ronye appear with Eugeo's and Kirito's swords and ask Alice if they can return them. Alice takes the two swords and let them talk with Eugeo and Kirito. Each one approaches their mentor. Tiese promises Eugeo that she would become an Integrity Knight and save him, while Ronye gives a bento to Kirito. Alice sits on the saddle and makes the Dragon rise and takes Eugeo and Kirito to the Axiom's Church Central Cathedral.
In the «Ocean Turtle», Asuna ascended a set of stairs to visit Kazuto and remembered all the times she had climbed stairs like those in Aincrad with Heathcliff and Kirito. While thinking, she encountered a robot descending the stairs. Higa Takeru appeared along with Koujiro Rinko and introduced the robot as Ichiemon. After saying their greetings they returned to the laboratory.
Back in the lab, Rinko and Takeru explained to Asuna about Ichiemon and how it is a part of the Alicization Project. Rinko took Asuna to eat breakfast, and on the way Asuna saw two males from the Rath staff whom she got a bad feeling from. Rinko asked what was the matter, but Asuna answered that it was nothing and they continued on their way.
Chapter 6 - The Prisoners and the Knight
Eugeo and Kirito were being held in a dungeon at the Axiom Church's Central Cathedral. There, they began to inspect the chains that were holding them and realized that they could break them with their own strength. Kirito then used the broken chains to break the cell bars using the whip techniques that Sortiliena Serlut taught him and found the jailer sleeping despite all the noise they had caused.
Eugeo and Kirito climbed a set of stairs and found themselves in a maze created with bronze fences, and even more amazing, filled with roses. They used Sacred Arts to locate their swords, but on their way to retrieve them they met another Integrity Knight, who presented himself as Eldrie Synthesis Thirty-one and explained that Alice had told him to wait there because she suspected that they would escape. Kirito began fighting the Knight just to be overwhelmed by his weapon and speed at chanting Sacred Arts. Kirito turned to his partner and both began to fight the Integrity Knight without their swords. Kirito managed to approach Eldrie taking advantage of an apparent opening, but at the last moment the whip Eldrie was using separated into two parts and struck both of them. Eugeo and Kirito took chances one after another to attack, but they were fruitless until Kirito managed to enter into a stalemate with Eldrie.
Eugeo jumped in for a surprise attack, but Eldrie used his last resource, the Release Recollection Art, and his whip transformed into a snake, which stopped Eugeo. While on the floor, Eugeo recognized Eldrie and, with Kirito's insistence, they made him enter a state of shock by reminding him of his memories, which were sealed by a strange prism that began protruding from his forehead, from his life before becoming an Integrity Knight.
After Eldrie fell, they were attacked by another Integrity Knight, this one using a red bow, from its dragon. Kirito and Eugeo ran through the maze into the plaza of the cathedral. Kirito heard a voice that guided him to a door, which they entered and managed to escape from the air attack.
After they crossed through the door, they found themselves in a strange hallway and a mysterious person had joined them. She prompted them to follow the hallway until they entered a strange room with more hallways, all of which then disappeared. The person was revealed to be a girl, but looked like a scholar. She took them through another door, which entered into the Great Library Room. The girl introduced herself as Cardinal, and made food for Kirito and Eugeo and told them that they could read as many books as they would like, but they must first recover from the previous battle. Kirito sat down to eat while Eugeo took a bath. Kirito talked to Cardinal and, as he predicted, Cardinal revealed that she was the embodiment of the Cardinal System. She took Kirito to another room and on the way he realized that she wanted to discuss something Eugeo could not hear.
In the new room she told Kirito about the story of Underworld, how it came to be, how the Feudal System was implemented, and revealed to him the real story behind the Taboo Index, the Axiom Church, and its founder Quinella. During the story, Kirito realized various things, but also learned that the Cardinal before him did not possess the authority over this world as the other Cardinal Systems do over other VRMMO games.
- In the web novel, the rape occurred before Eugeo arrived. The Light Novel has it so that the assault did not begin until Eugeo arrived.
- In the web-novel, Raios is killed by Eugeo
- The 6th chapter in the web version of Alicization, which was included before the web version's equivalent of this volume, was instead moved to Volume 15, as Chapter 14.