- A Crime Within the Walls and Murder in the Safe Zone redirect here. Not to be confused with the story in novel Volume 8.
On March 6, 2024, there was a meeting at the main town of the 56th Floor, Pani, where all the top players in the «Clearers» were discussing the advancement of the game. In this meeting, Asuna – the vice-commander of the «Knights of the Blood» – debated with Kirito intensely over strategies to fight against the Field Boss, GeoCrawler. Asuna's plan was to lure the boss into the town and then kill it while it was distracted by the «NPCs». However, Kirito objected as they would be trampling on the NPCs' lives, though Asuna coldly stated that they were merely "objects" to the game, thus they would simply respawn after being killed, unlike the players. She also reminded Kirito of her status and as thus he was forced to comply. Afterwards, Agil confronted Kirito about their constant bickering, causing Kirito to remember the advice about joining a guild that he had given to Asuna, and how amazing she had become.
Later, on April 11, 2024, Asuna found Kirito sleeping at a grass hill, within the 59th Floor's main town, Danac, and tried to tell him off for not working at the front lines. Kirito responded that the weather in «Aincrad» at that time was the best, and it would be a waste to be in the Labyrinth on such a day. After listening to Kirito's reply, she rested beside him to test his theory and fell asleep with him. When Asuna woke up from her eight hour sleep, she noticed Kirito watching over her and almost attacked him, before she remembered what had happened. To thank Kirito for protecting her as she was sleeping, Asuna tried to treat him to a meal at an NPC restaurant in the 57th Floor's main town, Marten. There, they discussed about the concept of «Sleep Player Killing», caused by forced «Dueling». Before they could eat, however, they heard a scream outside and hurried to investigate.
Upon arriving, Kirito and Asuna witnessed a murder within the city, which should have been impossible due to the «Anti-Criminal Code Effect Area» feature within a safe area in the game. A heavily armored player was hung by a rope in front of a church, appearing to have been pushed out of a window after being impaled with a spear, and finally shattering into blue polygons due to the «Continuous Piercing Damage over Time» effect. As the killed player was still within the city boundaries, Kirito believed that the cause of death was losing all his health in a duel with another player. However, the «Winner» notification for such a duel did not appear, eliminating that possibility. While investigating the murder case, Kirito and Asuna interviewed a witness, Yolko, who claimed that she was supposed to meet up with the victim, Caynz.
After retrieving the murder weapon and leaving Yolko in the safety of an Inn, Kirito and Asuna traveled to a player shop in the main town on the 50th Floor, Algade, to have it appraised by Agil. Agil deciphered that the weapon, named «Guilty Thorn», was created by a player named «Grimlock». Kirito attempted to test if the weapon could harm him inside the city, but Asuna stopped him before he could stab his hand. They exited the shop after leaving the weapon with Agil.
The next day, Kirito and Asuna met up with Yolko at the restaurant they had been to the day before, and learnt that Yolko, Caynz, and Grimlock were former members of the now defunct «Golden Apple» guild, which had lost their leader, Griselda. Yolko told them that after obtaining a rare ring from a monster, they voted whether they should keep or sell it and came to the decision to sell it with five people voting to sell it and only 3 voting to keep it. Griselda then went to the front lines to try and sell it, but never came back at all. Yolko mentioned that Grimlock was the leader's «in-game husband», and that the killer may possibly be after the three Golden Apple members who were opposed the selling of the ring: Caynz, Yolko, and Schmitt. By Yolko's request, Kirito and Asuna brought Schmitt to have him meet with Yolko.
During their conversation, Yolko told Schmitt that she believed that the killer was the vengeful ghost of their deceased female leader, Griselda, since no normal player could kill another inside the safe area. Suddenly, as Kirito, Asuna and Schmitt are watching the panicked Yolko, she was murdered in front of them, stabbed in the back from a dagger through the open window. As she fell from the second floor window, Kirito rushed to the window to call her name, but she shattered into blue polygons in front of his eyes.
- Guilty Thorn - for safekeeping
- Asuna and Kirito's argument at the beginning of the episode originally came from the first material edition and ended in a duel between the two, which Kirito barely won by using a feint of seemingly dual wielding. Eventually, the Geocrawler field boss was killed by playing a lullaby to make it fall asleep, instead of sacrificing the NPCs of the town.
- In the novel, the events of the Murder Case began on April 22, 2024, while in the anime it was April 11, 2024.
- In the light novel, Kirito, Asuna and Agil journey to the 1st Floor, where they confirm the death of the victim via the «Monument of Life» (which is later revealed to be a player whose name is similar in pronunciation to the alleged victim).
- In the light novel, Asuna was wearing casual clothes tailored by Ashley in the inn, before changing into her guild attire after Kirito complimented her looks too late.
- In the novel, Schmitt was the one who requested a meeting with Yolko, while in the anime, Yolko requests for a meeting with Schmitt.
- Asuna and Kirito's meal and conversation with Heathcliff is omitted in the anime.
- In the light novel, the Guilty Thorn was taken by Schmitt of the Divine Dragon Alliance from Kirito on the 48th Floor when Kirito was on his way to his accommodation at the time there, instead of being left with Agil for safekeeping.
- In the light novel, Kirito goes outside the Area and uses a throwing pick to test whether it is possible for piercing damage to harm a player within the Area and Asuna does not stop him from testing it, while in the anime he tries to do it with the Guilty Thorn at Agil's shop and he is stopped by Asuna.
- Though the Light Novel depicts Kirito in his Blackwyrm Coat and Asuna in her KoB uniform, the anime depicts them in different equipment.
- "No, the third is impossible. I kind of hate to admit it, but SAO's rules are essentially fair. I can't imagine this game allowing murders in safe areas." - Kirito