The Truth about ALfheim (アルヴヘイムの真実, Aruvuheimu no Shinjitsu?) is the twenty-first episode of the Sword Art Online anime adaptation, as well as the seventh episode in the Fairy Dance Arc. It aired on November 24, 2012.
Kirito and Leafa had finally arrived at Alne and were admiring the city. Suddenly, they heard the system announcing that the servers would be down for scheduled maintenance, and thus asking players to log out. Heeding the warning, Leafa suggested to log out at an inn. Kirito agreed but nowhere that was too expensive because he was out of cash, though Leafa teased him and said that it was because he had shown off by giving it all away to Sakuya. Leafa asked Yui, if there was a cheap inn nearby, and she pointed to the inn's direction and they began to walk into the city.
Meanwhile, Asuna ran through the branch pathway and spotted a cave-like entrance. Inside the cave, Asuna spotted a large metal door and placed her hand on the keypad, sliding the door open. The sudden movement frightened Asuna, causing her to run and hide. After a few seconds, she took a peek at the door and saw a long and brightly-lit hallway.
Back in the real world, Kazuto was washing his face and greeted Suguha in the morning. Noticing Suguha's drowsiness, he asked when she had gone to bed. Suguha told him that she went to sleep at 4:00 AM because she had been on the Internet. Kazuto told her that she should not be staying up that late, though he quietly thought that he was not the one to be saying that due to also going to bed at about the same time. He then told Suguha to turn around, and after she did so, Kazuto poured cold water down her back, causing her to scream loudly.
Meanwhile, Asuna cautiously walked through the hallway until she came across a map. She examined it and tried to find where the console to log out could possibly be until she noticed a label for an experiment room, and recalled Sugou Nobuyuki's plans.
Back in the real world, Kazuto and Suguha were making food. Unhappy with Kazuto's prank, Suguha demanded that him to buy her shaved ice and a parfait to apologize. He agreed, but not that day, as he had something to do in the afternoon, and was going to visit Asuna in the morning. This saddened Suguha, but she asked if she could come, which surprised Kazuto but he accepted the idea.
Meanwhile, Asuna went to the experiment room and there she found many pillar-like objects, each object was projecting the hologram of a human brain. Realizing that each brain was suffering from various negative emotions, she continued recalling Nobuyuki's plan and vowed to make him pay and liberate everyone, and told one of the brains to wait a little longer. Suddenly two slug-like monsters entered the room and began to monitor the projections. Asuna hid behind one of the pillars and tried to sneak away.
Back again in the real world, while getting on the bus, Suguha asked Kazuto about school. Kazuto told her that it was planned for one of the city schools to be used for students from Sword Art Online, therefore the school did not require an exam to enter and graduating from it would grant students the right to take a test at a university. Suguha thought it was a good idea, but Kazuto believed that they did this to observe them. He also states that even if he wanted to go to a regular school now, he would have to spend a year at a cram school. Suguha encouraged Kazuto and offered to tutor him.
In the experiment room atop the World Tree, Asuna noticed a floating black cube and believed it to be a system console, much like the black cube she found in SAO that was a Game Master (GM) console. She ran to the console and slid the card slot before many windows began to pop up. Asuna looked through the window menu and noticed "Transport" and the window asking to log out. However, before she was able to confirm the log out, one of the slugs approached her from behind.
Meanwhile, at Asuna's hospital, Kazuto and Suguha arrived at the hospital where he introduced the unconscious Asuna to Suguha and told his cousin about her status in SAO.
Back in ALfheim, Asuna was caught by the two slugs and pulled away from the system console. Asuna claimed to be a friend of Nobuyuki, but the slugs denied her claim, stating that he would not allow anyone in the Experiment room. They quickly recognized her as the one who Nobuyuki kept in the bird cage. Asuna then tried to reach the log out button by stretching her foot, but was restrained by one of the slugs. She then questioned the scientists about partaking in such an unethical experiment, but they responded that the victims were also allegedly having wonderful dreams. At that point, one of the slugs logged out to contact Nobuyuki in the real world while the one restraining Asuna attempted to molest her but had his tentacle bit, making him suffer pain as he had deactivated the Pain Absorber. Within moments, the other slug returned and stated that Nobuyuki was angry and ordered the scientists to return Asuna to her cage, change the password, and keep constant watch on her.
In the real world, Suguha commented on Asuna's beauty and how unfortunate it was that she was still sleeping. She then regretted coming with Kazuto and quietly began to question her own feelings towards her cousin as she was changing the water in the vase of flowers.
At the top of the World Tree, after the slugs locked Asuna back in her cage and left, she promised Kirito that she would escape from her prison. Asuna then revealed an admin card, which she had taken from the system console when the scientists were not looking.
At the bottom of World Tree, in the city of Alne, Leafa logged into ALfheim Online at the inn they logged off prior to the server maintenance. Kirito soon logged in after her, greeting a sorrowful Leafa who revealed that she was heartbroken. Kirito consoled her, saying that whether or not it is in a video game or in the real world, she could cry when she was hurt. Leafa cried on his shoulder, hoping to bury her feelings and forget them. After she regained her composure, Leafa, Kirito and Yui walked towards the base of the World Tree and gazed at awe. Kirito wondered how he could reach the top, but Leafa responded that the climbing area was an off-limits zone and reaching the top through flight was impossible due to the flight limit. When Kirito asked about a stunt attempted by five people, she explained that the Game Masters were greatly alarmed by the incident and immediately patched the game to prevent access to the World Tree by flight. As they continued walking, Yui detected Asuna above them, causing Kirito to suddenly begin flying to the top of the World Tree in a hurry, much to Leafa's surprise.
- Adapted from Volume 4
- Kirito and Leafa's adventure in Jötunheimr was omitted in the anime.
- In the novel, while traveling on Tonky, Leafa shoved a snowball down Kirito's collar and onto his back to awake him. That is where Kazuto later got the idea of waking the half-asleep Suguha by pouring down cold water on her back.
- In the scene where Asuna attempted to press the log out button with her foot while the slugs were talking about her, an earlier shot showed her reaching for the button with her left foot, but the following close-up shot showed her right foot instead.