NOTE: To start the quest, you must equip the Jewel of The Three, right-click on it, and "use". The spirit you need to talk to will appear.
Retrieve the walking chest: Find the wandering chest (again). It is roaming in Moors of Ykesha somewhere between Firmroot Moot and the canyon to Tupta (Ask a guard about the chest and it will mark it on the map once you start the quest).
Take the walking chest to the mysterious Archmage "within the city of the Highmen" -- talk to Bellengere the Three in Paineel at ( 1997, -299, 3362 ) /waypoint 1997, -299, 3362.
When Bellengere opens the portal for you, zone in.
You are now in Monolith Of Wrahzul (room 2), take a few steps to update the quest. This is a solo zone. No mercs either.
Is this Bellengere's study or was this a trap?
Exit the Monolith through the portal on the other side at ( -0, 13, -157 ) /waypoint -0.4, 13, -157. The exit is very close across the room and you can just run there without fighting.