Gond Orchal has been corrupted by a gaunt-lord who is raising Wights from the various tombs. This evil must be defeated.
'A Gond Orchal war-monger is corrupting the tombs in this area. Defeat the risen Wights and the gaunt-lord at the top of the hill.'
Speak with the mission giver to travel to the tomb. Defeat Wights and the Gond Orchal war-monger.
With your mission in Gond Orchal successful, you should return to the mission giver.