Ok, so pretend we come out of this fight without losing anyone. (BTW, I have my gnome bard all set to go!) What next? The vampire is useless regarding any further information on the cult. He's actually told us that (see the DM Tabletop forum). This essentially means the cult thread is on hold. What next?
I've learned from Nathaniel, innkeeper of the Rusty Axe, (fitting I'm speaking about him in this forum, isn't it?) that dwarves are delving tunnels all over [under] the city. The officials aren't pleased. Now, remember, we've just entrusted our friend Flooty McSnooglemuffin (can't remember his name, but it starts with an "F") to shore up our HQ. I'm not saying he's part of this Big Dig the dwarves are putting on, but it would be pretty convenient for him if he was.
I can imagine him going back to his dwarf friends and saying, "You'll never guess what this stupid lot of adventurer's have given me access to--their underground lair! Now, here are my plans to connect this lair to whatever horseshit you guys are planning...."
I may be paranoid here, ha!