One day, Cayna receives an urgent correspondence from Shining Saber, a fellow Leadale player also transported to this new world. It turns out that a horde of monsters is headed for the royal capital, and he needs Cayna to lend her mighty powers to stop the beasts. But when a Guardian Tower in the form of a giant tortoise appears in Cayna's absence, will Exis and Quolke have what it takes to handle it themselves?!