Delving deeply into the world, the forces of the enemy are incredibly powerful and vicious.
The stone is inert. There is a clear fissure in the surface where one, with a little effort, could affix a gem of some sort. Perhaps you have such a gem in your possession.
You must place a delving amethyst into the fissure in the delving stone. This will unlock the potency trapped within the gemstone and unleash it upon the world.
A malice spread from within the gemstone you affixed to the delving stone. You must defeat the enemies to rid the evil from the world.
Having completed the mission with the malice affecting the denizens within, you should now make your way back to a mission giver who knows about delvings, and tell them of your success.