Koren gets out the map and journal and checks his directions. As best as he can tell, turning right at the t-juncture should get you to a passage that dead ends at a the door where the map dead ends as well. At that point, you ar eon your own.
The four of you walk carefully down the sewer line, eyes and ears even more closely looking out for ambush. You walk over a grate set into the floor and are finally on dry land for about twenty feet when you approach a circular metal hatch, set into the tunnel wall and engraved with arcane runes. The passage continues on, but this looks to be roughly where the map Elaydren gave you indicates. In the middle of the hatch, a glowing circle of mithral depicts the same icon as on Bonal's journal-the ancient symbol of House Cannith, a stylized anvil and hammer.
((OOC: It looks like we've lost Karl. I'll NPC Grim until the end of this adventure and then we'll start looking for someone else. Sorry for the delay, I guess I just kept on hoping))