An examination of the map and notes has you checking out the Temple Grounds Cloud station.
Explore around the Temple Grounds Cloud station.
You will find an X made out of stones on the ground at -262.46, -19.46, 18.73 , near the cloud station to Vultak Scavenging Site.
Clicking any of the stones instantly teleports you onto a hanging branch underneath Temple Grounds isle, walk forward along the branch to the treasure!
Find an X on the ground, click it, and follow the line to the treasure.
Ride the updraft back (click the blue sparklies on the root). Note: If you converted your cloud mount into a house item before clicking the blue sparklies, change it back into a mount to be able to interact with them.
You take a close look at the map and look at the four main islands you had to visit earlier in your quest. After a moment of pondering, you connect the dots and discovered that it makes an X right over where the Temple Grounds Cloud station is. You should go there and see what you can find.
Search around the area of the north-eastern Temple Grounds cloud station for clues.
Search for clues that might lead to the lost treasure.
You found the lost treasure.
You found the hidden treasure below the islands in a secret cave.
Return to Bilgeron Cogsworth on the Temple Grounds.
Return to Bilgeron.
You returned to Bilgeron.
You returned to Bilgeron Cogsworth on the Temple Grounds.
You found the hidden treasure of the Kingdom of Sky, and though it is small, it is valuable. In addition to assisting the L.O.S.T. exploration team locate the missing Drednever expedition, you have also turned quite a personal profit from your involvement!