Ashmelech is a very long way from Narsis. You can take guild guides to Sadrith Mora, then travel by boat to Dagon Fel. Use recall to return to Narsis, just remember to put your mark outside the guild hall.
The following Journal ID and Index codes can be used with the Journalconsole command to manually update the quest to a certain point.
Passwall (TR_m7_Ns_MG_Arch02)
Index
Finishes Quest
Journal Entry
10
Ralsa Ondusi told me to ask the mage Katylinwe of Telatessa for insight on reconstructing Passwall. Katylinwe lives in the Foreign Quarter of Narsis.
20
Katylinwe of Telatessa told me that an old rival of hers, Dhaunayne Aundae, has an Amulet of Passwall. Dhaunayne Aundae is the head of a vampire clan hiding somewhere on Vvardenfell.
24
Gilimeg told me that he heard Skink-In-Tree's-Shade is involved in research about vampires on Vvardenfell. Skink is in charge of the Mages Guild in Sadrith Mora.
28
Skink-In-Tree's-Shade told me that the Aundae vampire clan's main lair is called Ashmelech, an ancestral tomb on an island southwest of Sheogorad.
30
I brought Dhaunayne Aundae's inert Amulet of Passwall back to Ralsa Ondusi. She said that we may be able to reawaken the spell inside it using the BALROG, and told me to meet her in the Genatorium of the Narsis Mages Guild.
40
I met Ralsa Ondusi in the Genatorium. She gave me the gem from the Passwall amulet and told me to place it into the containment field above the BALROG.
100
Finishes quest
Ralsa Ondusi repaired the Amulet of Passwall. She told me to bring it back to Lord Mhas Vathor.