The episode begins on December 28, 2025, with Suguha showing Kazuto (Kirito) a news article about the discovery of the legendary in ALO. This triggers a flashback to when Kirito and Leafa first discovered the sword months earlier while trapped in Jötunheimr , a frozen underworld beneath ALO. During that time, they rescued a beast-class evil god they named Tonkii , who showed them the sword's location in an ice dungeon.
: If Tonkii's kin are wiped out, Urðr will lose her power, allowing Thrym to invade ALO.
: Thrym, the King of the Frost Giants, threw Excalibur into Urðr's Spring, severing the World Tree's connection to Jötunheimr and turning it into a wasteland. Sword Art Online II Episode 15
: Yui explains that Urðr is more than a simple NPC; she is connected to the Cardinal System's language engine , making her a sophisticated AI capable of complex interactions.
: Thrym promised Excalibur to players who help him slaughter the beast-class monsters, but he intends to give them a fake sword. The episode begins on December 28, 2025, with
: Reviewers from sites like Geeks Under Grace and Anime News Network noted the sharp contrast to GGO, describing this arc as "exposition and setup" with a more traditional MMORPG feel.
Realizing that many other players are now hunting for the sword, Kirito assembles a seven-person party to claim it first. The group includes: (Spriggan) Asuna (Undine) Leafa (Sylph) Silica (Cait Sith) Lisbeth (Leprechaun) Klein (Salamander) : If Tonkii's kin are wiped out, Urðr
(Cait Sith), who has converted her character from GGO and uses a bow. The Quest: "The Holy Sword of the Ice Palace"