In Hunted: The Demon’s Forge you may come across a few side quests. “Hearth of the Dead” is one that you will find during Chapter 4, Section 2.
Navigate around the courtyard that’s falling to pieces. You should come across a skull that is set on the mantle of a fireplace. Now, activate the skull, which will tell you that he was imprisoned in that location by a warlock. This activates the side quest.
The skull will also ask you to collect his other parts that are scattered around the courtyard. The different pieces of his skeleton should not give you any trouble, as they are quite easy to find. After you collect them, a flame will appear. The skull asks you to bring that flame to his “love” on the other side of the wall. Shoot at that skull with the lighted arrow to activate her. She will tell you that she was actually the wife of that warlock that the first skull told you about.
She’ll give you a reward, telling you about her husbands treasure, which is behind his black heart. All you need to do is re-enter the courtyard, go to the far left, and move the wall with the black heart on it out of the way. Your reward is a lone Dragon Tear. Upon collection of your reward, the quest will end.