What do I need to get through the door behind the lich? I found the key, but I only have one badge. Do I need the other five badges? If so, where do I find the other five badges? The only badge I could find was in Dorn's in the cave after you go over the rope bridge. Please help and/or let me know what other information you need to help.

Thanks in advance!

You need to consult with the dwarven ghost. He will tell you the where the key is but when you return be prepared for a fight. Cheers

Not sure what the problem is here. You should only need the one badge (from the caves with the Umber Hulk/Red Wizard of Thay) and the door key (dwarven forge compartment by the ghost - active forge). That's all I had and I just got through it last night. I think if you had to fight the Golems in front of the door you must have had the "right stuff", otherwise you wouldn't have triggered them. Hope this helps. Good Luck!