There is much for the White Company to accomplish in reclaiming Minas Ithil from the remnants of Sauron's forces.
'Many horrid things hide within the Deep-barrow of Gorthad Nûr. If you are to venture inside, I ask you to destroy the corrupted runes within. Their foul sorcery continues to rally the dead and must be stopped.'
Corrupted runes can be found in Gorthad Nûr, the Deep-barrow.
You should destroy the corrupted runes.
Destroyed corrupted runes within Gorthad Nûr.