See also: Puzzles
The lamps periodically spawn and de-spawn, just position yourself in the middle of the circle and click on them to turn them on. Once the entire ring is lit, you will receive a loot box with A Rusty Key inside, and a chest spawns in the middle of the ring of lamps. Open the chest to receive A Dusty Sack which will yield an uncommon, rare, or epic quality item related to your level and some gold.
If you complete the puzzle again, you will receive A Dusty Sack which will yield at least one trash item worth 1 silver each.
A change corrected the breath bar for this quest. When it hits zero, you drown. If you manage to solve the puzzle in time you will receive a buff that will let you breathe underwater so that you have enough time to finish looting.