I am to find the prepared location within the Reet Slave Mines.
The location in question is a carpet located at ( -108, -112, 408 ) /waypoint -108.38, -111.89, 408.32 in the Reet Slave Mines. This is on the same level as Venril's Scale from the quest before, through the gates south of Venril's Scale.
Click on the carpet and you will receive some quest text indicating that this must be the place.
Examine the scroll you received from Enchanter Glowwp and further the dialog that pops up.
NOTE: the carpet will disappear after a couple groupmates click it so try to get everyone to click it at the same time.
UPDATE: I was 3 boxing and did all 3 and the carpet stayed put even after I completed Quest.
NOTE: you can do the quest Reet Seeking along with this quest as it is on the same level and easily accessible from here.