Mysterious monsters appear as Naofumi is preparing for the next Wave. At the same time they show up, the Wave countdown stops. The Queen summons the Four Cardinal Heroes, and tells them that the Spirit Tortoise has revived.

The Spirit Tortoise begins its march once more, appearing at the border of the kingdom bearing its name. Naofumi volunteers to lure away its familiars while the army tries to bring it to the mountains. The Spirit Tortoise's familiar, Ost, fights alongside the humans…