Following his first journey to the Crystal of Yggdrasil, Aki is shaken and confused. He still can't believe that the gods and creatures he thought existed only in mythology are actually real and living. But he will have to get used to the idea very soon, because this is just the beginning of his new life as an heir to the Superior Beings. In fact, Aki finds out that a very close friend, and the last person he would have expected, is an heir like himself. The young girl has the gift of oneiromancy, a gift that allows her to see the future through dreams, and she is certain that something very troubling is about to happen. With the help of the Sphere of Time, the two friends will embark on a risky mission on the Crystal of Nammu. Accompanied by the loyal cat, Timoteo, and guided by a powerful demigod, the journey will be rife with perils from the Gallu demons to the goddess Ereshkigal, until the truth is finally revealed before their very eyes.