You learned that Gwyllion, the Old Woman of the Mountain, is in league with the traitor Saruman. It is likely that she is responsible, as well, for the appearances of evil creatures in the Windfells.
'So, ${PLAYER}...from what you have told me, it appears that Gwyllion is indeed in league with the traitor Saruman. I expect she is also responsible for the apparitions which have been troubling the Uch-lûth.
'Return tonight, ${PLAYER}, and confront this sorceress. Perhaps with her gone, the Uch-lûth may be able to live without fear.
'Speak with me again when you are ready to leave.'
Saeradan is at Echad Saeradan in the Windfells of Enedwaith.
You should return to Saeradan with news of your victory against Gwyllion.