If Rovalang saw a Nazgûl on its winged steed, it must be prevented from learning of Aragorn's passage with the army of the Dead, at any cost.
'You have heard of this winged creature, ${PLAYER}... I can see it in your eye. Will you help me find it and keep it from harming the people of the Vale?'
You nod in agreement. If the Nazgûl learns that Aragorn commands an army of the Dead, much harm might be done to the desperate hope that drives him, and to the people that depend on him.
'Well, let us go at once! If you have a Fellowship at your call, bring them along as well. There will be danger enough for all... but now let us chase this foe! I saw it fly in the direction of the haunted cave to the north-west. Perhaps we can bring it down, if we hurry!'
Rovalang is on the slopes of the Hill of Erech, in the Blackroot Vale.
The Nazgûl must be prevented from learning of Aragorn's passage with the army of the Dead, at any cost.
Rovalang is on the slopes of the Hill of Erech, in the Blackroot Vale.
With the help of Rovalang, you have driven off the Nazgûl that threatened to learn of Aragorn's passage with the army of the Dead.
Lothíriel is in the Great Hall of Dol Amroth.
You faced a Nazgûl in the Blackroot Vale, and though it has been driven away formless to its master, this is a clear sign that the Great Enemy has Gondor much on his mind.