The Secret Revealed (item)

Deepvein gives The Secret Revealed to you and asks you to kill his former companion Coldhearth, who has betrayed the brethens and transformed himself into a lich.

The item has only three charges and only Deepvein can recharge it.

In-game description
"This green gemstone glows with the power of Dumathoin, the Keeper of Secrets beneath the Mountain. Its divine power exacts a heavy price on the undead, especially liches."