A phenomenon called the Snow Sea engulfed the surface world, and only a handful of people now reside high above the Snow Sea. When Kaina, one of the members of the last remaining village, goes on a hunt, he finds something entirely unexpected...

Kaina and the other villagers find out for the first time that there is life below the Canopy. Ririha, princess of Atland, explains that she came from the Snow Sea in search of "the sage," who may be able to help with their water shortage issue.

Drunk on power, the Admiral continues to operate the Builder and is determined to kill the King. Ririha tries to save her father, which results in making herself the Admiral's target. Will Kaina make it in time to save Ririha?