Rudeus and his father Paul have traveled the world to rescue all the members of their scattered family, and the final obstacle to their happy reunion now stands before them. Rudeus's mother Zenith is imprisoned by a vicious hydra, a beast of legend that won't go down without a fight! Father and son will do whatever it takes to bring her home, and prepare to put their lives on the line alongside a party of veteran adventurers. The raid on the teleportation labyrinth reaches its tumultuous conclusion!