I'm at basement 3 (think I cleared everything) and 4 in the dungeon you can enter from the 'village' in the desert. Got the green, pink and yellow crystal. I know where and how to get the red crystal but it is in a treasure chest. Does somebody know where to get the key for that one? Is it a drop from a creature or something like the harpies or the golem? Or am I missing something. 'Cause with the search magic I couldn't find it and those creatures are tough to beat.