Sword Art Online: Calibur summary: ソードアート・オンライン キャリバー The goddess Urd is in danger, and only Kirito and his friends can save her! The evil frost giants have invaded her homeland of Jotunheim, bringing death and destruction in their wake. The linchpin of it all is the frost giant king's sword-the legendary weapon Excalibur! If Kirito's crew can make it to the end of the dungeon and pull the sword from the stone, peace will be brought to the land once more! Source: Yen Press Note: Covers the Calibur Arc from a side story in Volume 8 of the light novel series.