Access to this dungeon is complicated, see quest for details. The gland flag lasts two hours, once you have passed through the portal at the end of the Sealed Olthoi Passage at least once, you can reenter the lair using a backdoor portal located in a bunker at 44.5N 57.3E just east of Pardox-touched Valley. There is a door just before the portal that is opened by using the lever in the far right corner of the Lair on a small platform (Olthoi Cistern).
