I have doucmented the solution for this quest, I just don't have it up on the web yet. But here's the draft text for A Dark Ohm:
Head west from the Aman'lu teleporter and walk down the ramp and straight ahead, turning south into the Magic Shop before reaching the entrance to the Aman'lu Tavern. Head through the ante-room back into the main room and speak to Mage Lyssanore. Chose the second option relating to spirits. Agree to find a Vai'kesh ritual chamber in the Vai'kesh Forest and eavesdrop on their chanting to learn of their chants to contact the dark spirits, to initiate the quest.
In Chapter 5 of the main quest in Act II, which is The Vai'kesh and the Aegis of Death, once your party is in pursuit of the nasty Prophet, who ordered their deaths, they'll enter A Large Vai'kesh Cavern from the Vai'Kesh Forest (the entrance is right behind the Vai'Kesh Forest teleporter). Have them fight their way through this cavern. As they emerge from the cavern, they'll activate the Vai'kesh Forest South teleporter. Head to the northeast for a short distance and a cut scene is shown of the Prophet riding off across a bridge to the east, while exhorting his minions to destroy your party. Deal with them, then head into the cave from which the minions emerged. It's called A Small Vai'kesh cavern and is just to the north of the bridge the prophet crossed over. Take care of the welcoming committee. Continue north to a door and open it, which will cause your party to observe and overhear their ritual. Deal with any enemies who come to the doorway. It is not neccessary to head down into the pit and take out the chanters before returning to Aman'lu, but you can if you wish. Teleport back to Aman'lu from within the cavern if you have a mage with the teleport skill, else head back outside and backtrack just a bit and do so.
Head west from the Aman'lu teleporter, then turn south and enter the Magic Shop and speak to Mage Lyssanore and she'll observe a pale tinge to you characters' skins and note that they did in fact overhear the ritual. She'll ask that the chant be repeated slowly to her, then says she'll share it with your party and they receive the Chant of the Dead. Chant it at any Incantation Shrine and they'll be able to converse with any nearby ghost. You can also teleport after having done so, even from Act to Act, and the chant will of course be still in effect. This completes the quest.
[This message has been edited by rayearle (edited 10-05-2005 @ 00:13 AM).]