-- go talk to Abdullah. Notice the sparkle on the scaffolding before you talk to him; it's a key.
Hint 4
Tell him about the new sarcophagus, and he immediately rushes off to go see. While he's gone, take the key, aha!
Hint 5
Go back to the residence tent; if Lily's there, tell her Abdullah wants her, and the place is yours.
Hint 6
Inside Abdullah's trunk, you'll find two letters that raise more questions than they answer. Better go talk to the people involved and see what they have to say.