On December 28, 2025; Kirigaya Suguha (Leafa) showed her cousin, Kirigaya Kazuto (Kirito), a news article about the legendary item, the «Holy Sword Excalibur», being discovered in ALfheim Online. Kazuto recalled that several months ago they both ended up in Jötunheimr and saved a flying evil-god-class monster, whom Leafa named Tonkii. The monster showed them a labyrinth that had Excalibur and Kirito planned to take the sword at some point, but he was too busy to do so. Kazuto was surprised that someone else discovered Excalibur, and Suguha suggested that someone may have saved Tonkii's kin and triggered the quest flag to retrieve the sword. Kazuto believed that Tonkii wanted them to retrieve Excalibur.
Without delay, the two called Asuna, Klein, Lisbeth, Silica and Sinon to challenge the dungeon in the sky of Jötunheimr, where Excalibur was. While the group prepared their items at Lisbeth's Arms Shop and Asuna, Leafa and Yui searched for information on how other players discovered Excalibur while purchasing potions for the adventure. When the girls returned, Yui revealed to the others that there was a slaughter quest in Jötunheimr that revealed Excalibur's location. Once they were ready, the group entered Jötunheimr via a secret passageway in Alne. At the end of the tunnel, Asuna used a cold resistance spell on her comrades, and Leafa called Tonkii. The group climbed on Tonkii's back and asked it to ferry them to the ice dungeon. However, along the way, Tonkii suddenly dived and stopped at an altitude where they could see the ground. There they saw that players were cooperating with the humanoid evil-god-class monsters to massacre Tonkii's kin, the beast evil-god-class monsters.
As they were watching the scene, a giant NPC, the «Queen of the Lake» Urðr, appeared behind them. The NPC explained that the massacre was ordered by the king of the giants, Thrym, who once threw the Holy Sword Excalibur into Urðr's Spring and caused the world of Jötunheimr to turn into an icy wasteland. She then explained that if all of Tonkii's kin were slaughtered, she would lose her power and this would allow Thrym to invade the land of the fairies, Alfheim. She then gave them a medallion that would indicate the number of the remaining creatures. To prevent the invasion, Urðr requested the fairies to retrieve the Holy Sword Excalibur from the bottom of the ice dungeon, called Thrymheim, initiating the quest «The Holy Sword of the Ice Palace».
- Kirigaya residence
- Yggdrasil City
- Lisbeth's Arms Shop
- Adapted from Volume 8, Calibur, Part 1-3
- The scene where Klein complained about magic and the Sword Skill update was explained was not part of the original story.
- The anime did not mention that the usual route to Jötunheimr involves going through a stairway dungeon and beating the boss guarding the entrance to Jötunheimr.
- Kirito's suggestion for allowing other players to use their shortcut for a toll was omitted.
- The anime omitted that Thrym turned into a wolf to infiltrate Jötunheimr.
- The insignia of Lisbeth's shop says "RWS", even though "Lisbeth" is written with an L instead of an R.
- "Quest Accepted" was misspelled as "Quest Accepeted".