I think you need to do Kamasylvia main quest chain first and then this quest chain will show up. You can get it from Murizera and it's called Murizera's Curiosity. The quest which gives you the knowledge is The One Whose Voice Once Filled Grándiha. It took some energy, maybe 10, I'm not sure.
Nachdem die Kamasylvia Haupt Quest in Trent abgeschlossen wurde, bekommt man von Murizera auf Grándiha die erste Quest der Reihe "Murizeras Neugier". In folge der Quest Reihe muss man sagen wessen Stimme einmal Grándiha gefüllt hatte, die Antwort kostet 20 Energie und lautet Katharina. Dann erhält man das Wissen und kann die letzten Quests der Reihe machen.
After the Kamasylvia main quest in Trent has been completed, Murizera on Grándiha offers the first quest in the series "Murizeras Curiosity". Following the quest series you have to say whose voice Grándiha once filled, the answer costs 20 energy and is Katharina. Then you get the knowledge and can do the last quests in the series.