Required quests
Main dialogue
..I am sure .1101002 gave you a thorough outline, so I will just go straight to the facts. As you know, Ereve is an island protected by the Shinsoo. Any form of darkness is not only forbidden from winning, but even if it does enter, it'd be detected right away and be promptly removed.
Unfortunately, we weren't able to do that this time, and... that's because... we did not acount for who the thief was. The culprit wasa member of Black Wings, 9001009 1104001... We were unable to locate him even after entering this island, because he was in disguise.
The treasure should NEVER end up in Black Mage's hands. 9001009 has yet to escape Ereve, so you must participate in this search as well. Go visit 1101002 and receive 4032179.
Now... Go defeat 9001009... And bring back the treasure... I, as well as other Knights, will also be conducting the search.
Accept
9001009 is most likely disguised as one of the Knights. The appearances may change, but the inner self won't, so I suggest you keep talking to various Knights until you hear something that doesn't sound like it would come from a Knight. If you do, you can consider that individual 9001009 and attack immediately.