Centurion Sueros at the Undirborg Observation Post told you of a secret room in the Underground of Undirborg. A Reian had been abducted and taken there, and came back afterwards. Sueros asked you to look into the matter. When you spoke with the Reian Elder, he recommended you speak to Titus. Titus was the one who had been abducted. Titus told you that he had been abducted by members of the Dragonbound and taken to the Udas Temple. He claimed he discovered a Hidden Library where he saw a living Petralith. You defeated Shura Steadfast as Titus instructed, and by using a mechanism in a Drakan Stone Statue managed to gain access to the underground temple. There, you not only established that Petralith exist, but also obtained a Research Journal. Upon returning to Sueros, he admonished you for entering a place as dangerous as the Udas Temple without a backup. Yet he thanked you and rewarded your courage.