Sword Art Online Episode 21

The Truth about ALfheim (アルヴヘイムの真実) is the twenty-first episode of the Sword Art Online anime adaptation. It aired on November 24, 2012.

Plot
Kirito and Lyfa finally arrive at Aarun. While admiring the city, a voice of the system announces, "The servers will be down today from 4:00 AM to 7:00 PM due to a scheduled maintenance and that players are asked to log out 10 minutes before then." Lyfa suggests to log out at an inn. Kirito agrees but nowhere that is too pricey because he is out of cash. Lyfa teases that it was because he was showing off by giving it all away to Sakuya. Lyfa ask Yui, if there is a cheap inn nearby. Yui points to the inn's direction and they begin to walk into the city.

Asuna is running through the branch pathway and sees a cave-like entrance. Inside the cave, Asuna puts her hand on the keypad and the door begins to slide open. The sudden movement frightens Asuna, causing her to run and hide. After a few seconds, she takes a peek at the door and sees a long and brightly-lit hallway.

Back in the real world, Kazuto is washing his face and greets Suguha in the morning. Noticing Suguha's drowsiness, he asks when she went to bed. Suguha tells him, she went to sleep at 4:00 AM because she was on the Internet. Kazuto tells Suguha to turn around. She does what he said, resulting her in getting cold water down her back.

Asuna is cautiously walking through the hallway when she notices the map of the floor. She is looking at the map and tries to find where the console to log out could possibly be until she notices a label that said "Experiment". She recalls Sugou Nobuyuki's plans.

Kazuto and Suguha are making food. But Suguha is still mad at Kazuto's prank, so she demands that he should buy her shaved ice and a parfait to apologize which Kazuto agrees to. Kazuto tells Suguha that he is going to visit Asuna in the morning. This saddens Suguha but she asks if she could come, which surprises Kazuto but he accepts the idea.

Asuna goes to the "Experiment" room, and in the room was many pillar like objects and on each object was projecting the hologram of a human brain. Realizing that the "brain" was suffering, she vows to save everyone by making Sugou Nobuyuki pay. Suddenly two slug-like monsters enter the room and begins to monitor the projections. Asuna hides behind one of the pillars and begins to sneak away.

While getting on the bus, Suguha asks Kazuto about school. Kazuto tells her that they are planning to use one of the city schools for students from SAO, Kazuto believes 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 encourages Kazuto and offers to tutor him.

Asuna notices a floating black cube that is the system console. She runs to the console and slides the card slot before many windows begin to pop up. Asuna looks through the window menu and notices "Transport" and the window asking to log out. Before she is able to confirm the log out, she gets caught by the two slugs. After some struggle, Asuna manages to obtain the card from the system console without the two 'scientists' noticing and was later taken back to the birdcage.

After Kazuto introduced Asuna to Suguha, she comments on Asuna's beauty and how unfortunate it is that she is still sleeping. Suguha then feels regret for coming with Kazuto and begins to question her own feelings towards her cousin as she changed the water in the vase of flowers.

When Asuna is locked in her cage once again, she promises to Kirito that she will never give up and that she will eventually escape, revealing the card in her hand.

Lyfa logs into ALfheim, in the inn they logged off prior to the server maintenance. Kirito soon logged in after her, greeting a sorrowful Lyfa who reveals that she is heartbroken. Kirito then consoles her, saying that whether or not it is in a video game or in the real world, you cry when your hurt. Lyfa cries on his shoulder, hoping to bury her feelings and forget them. After regaining herself, Lyfa, Kirito and Yui walk towards the base of the World Tree until Yui locates Asuna right above them, resulting in Kirito blasting off into a rapid ascension towards the World Tree.

Locations

 * Aarun City
 * World Tree

Adaptation Notes
Sword Art Online Light Novel Volume 4
 * In Volume 4, Chapter 5: Kirito and Lyfa's adventure in Jötunheimr was omitted