Lazilus Castle: Great Hall
The chapter starts with a cut-scene in the castle. Afterward Zael will be on the East bridge in the city, Quark shows up to chat with him. Notice that as Zael travels through the city, people start referring to him as 'Kishi-sama/Sir Knight' instead of 'Hey you' or other things if he bumps into them.
At this point Zael is unofficially a Knight in the service of Ruli Castle.
Head back to Ariel's Tavern and chat with Zael's friends. Afterward go back to the Castle.
A bit of story narrative and a cut-scene with Zael at the balcony. Zael will hear something or someone singing.
Inside the ballroom, Seek the doorway upstairs and go to the living area. Move past Calista's bedroom and Seek the door back to the main castle area, and enter.
Zael will notice that no one else can hear the song but him. Head to the second floor. Seek the door to the Courtyard and move on. While in the Courtyard, Seek again to the hidden underground lift. Take the lift to the Underground Depths.
In the Depths, open the doorway to the right. Zael will be in the ruins, and as he travels further in, he will run into Kanan.
Examine the wall with the hole in it. Zael will kick it open (twice). Examine the stone tablet behind the wall for the next scene. The doorway opens and Tasha ends up tagging along. Head toward the light to go to Chapter 31.