Caliber SS is an alternate ending for Sword Art Online Light Novel Volume 08. It answers the questions: What if Klein decided to not save Freyja? What would the outcome be?
Plot
Klein exclaims after seeing Kirito perform his outside system skill, Skill Connect, to what Kirito doesn't pay too much attention. Then Leafa informs that they have almost one hour before the quest ends in failure, so they start running towards the next floor. They encounter a NPC asking for help, but because it could be a trap they leave her and continue their way to the other floors.
They pass the third floor in just eighteen minutes using Yui's help to guide them through the corridors and solve puzzles. They defeat the local boss and head to the last floor, finally arriving at the Boss room. Asuna casts buff spells as they prepare for battle.
They fight bravely with all they had, but then time runs out while half of the boss's life remaining, laughes at them while ejecting them from the Þrymheimr castle and makes his castle ascend to the surface, destroying Aarun, along with the players houses and items. As Kirito and the others watch the mass destruction, Yui informs that the items were refunded in money and others were stored in its owner storage. Suddenly appears a GM called Marinca, who is happy to know that the items were saved and explains them that this chaos is mostly her fault.
After talking with Marinca they decide to try to stop Þrym again, but they'll wait one and a half hours to rest and try again. Kazuto wakes in his bed and starts thinking, Suguha enter his room and they lie in the bed, and Kirito tells her that everything will be fine, then he starts thinking and notices that they committed an error in leaving Freyja, and because of it, they failed the quest.