Dunmeal
The big bad (Kadrick) also has the portal plate, which is the key through a portal in the dwarven underground roads (the Maldir). Our heroes need the portal key to have any hope of catching up to the 3 evil armies heading north to Yggdrasil, the Tree of Life. This is their main mission now, and the reason they came to Sloss Hinterplatz, the dwarven stronghold.
This life trapping mirror is said to hold the soul or spirit or something of that sort of a close friend of Dunmeal's.
Dunmeal's plan required two skilled dwarves, an animal trainer named Oscaronious, and an acrobat named Beindra. Our heroes recruited the animal trainer, who is with them now, but had no luck finding the acrobat. The acrobat would get them into Brazmird Hall (Kadrick's "castle") by climbing the furnace smokestack and sneaking in on the one day that the forge fires will not be burning, the holiday of Zanbar Kelvyn, which happens to be tomorrow. The animal trainer was to use his tiny trained miniature nuglets to open the complex lockboxes the items are stored in.
Our heroes don't know all the details of Dunmeal's plan. He was going to explain it all today after the party recruited the acrobat and the animal trainer. He did, however keep detailed drawings and notes in his cellar hideout where Mord and Rakanishu were just scouting around a few minutes ago.