Idmar wants you to track down and confront the leader of the shades. He has given you a token of his people, the descendants of Eorl, in hopes that the shade will recognize it. He has surmised that the leader must be stationed among the vast number of spirits at the camp to the west.
'I think I have a plan, ${PLAYER}. You have been of great aid thus far, and you should be the one to take up this charge.
'They must have a leader, nestled deep within their forces. Judging by the size of the force, I would guess that he lurks among the spirits of his men to the west.
'Here, take this, a symbol of my people. Hopefully, he can recall the battle and remember that the horsemen of the North once saved his people from certain defeat. Find out what he knows of the curse and why his men have returned if you can. I can only hope he has more to say than the others.'
The Oathbreaker captain lurks among his men atop the hill to the west.
Idmar has asked you to find the captain of the shades.
The Oathbreaker captain's men have sprung forth to guard him. They must be defeated if you are to continue your charge.
A peculiar skull is impaled on a nearby tree...perhaps this is the key to drawing the Oathbreaker captain forth.
The Oathbreaker captain is atop the hill to the west of Idmar's camp. You should attempt to speak to him now that he has revealed himself.