Help, I am missing the last piece of the disc which alows me to open the door down into what I presume is the Shadow dragon's lair. I have two pieces one from the cell past the word puzzle and another but I keep searching for the last with no success any ideas? I can't wait to have a crack at that blasted Dragon!!!!

The last part of the disc is in the cell whith the shadow asking for help (also past the word puzzle)