Ghorak is a man who was cursed with an unnamed disease for killing his brother, Kereph. Ghorak looks and moves like a zombie. He can be found in a locked house in the southeast section of the Baldur's Gate Docks.
When spoken to, he will warn you away, shouting that he is diseased. If the you offers to cure him, it will start his quest. He tells you that potions and spells are useless, but then asks them to find his brother's skull and bring it to the Temple of Tymora if they wish to help him.