"You must have completed the Dasha Vestibule mission before being allowed access to the explorable area." - This seems to be incorrect; my Nightfall monk has Master of Whispers rather than Margrid, and is therefore unable to take the Dasha Vestibule mission, but is granted entry to the Hidden City by the Key of Ahdashim. I suspect that progress through the game may be a factor; she has reached the Gates of Desolation so far. 81.152.20.83 11:24, 20 January 2007 (CST)
I think if you've finished Dzagonur Bastion, you can get access also.
unable to complete mission
you can complete such a mission with another persons hero... or just wait till you complete the game...