Book 2

In Underworld, a virtual land from which there seems no escape, Kirito meets Eugeo, an NPC destined to follow his Calling-his life's goal that must be achieved before he can follow his own path. What awaits Kirito in this new land?

Book 4

After Ronie and Tiese try to save their friend from the clutches of noble knights Raios
and Humbert, they end up getting captured themselves! With the two girls bound and
helpless, Kirito's going to need Eugeo's help to save them...but Eugeo finds himself
paralyzed by the thought of breaking the Taboo Index! With the fate of his page
hanging in the balance, can he violate his world's most sacred code to rescue her?