Corunir reacted strangely to the presence and touch of the stone-heart, recoiling from it in terror. He told you that the heart had been prepared to receive a fell spirit from an elder Age, similar to those that inhabit the wights which serve Angmar.
'Nay, take this evil thing... I can bear it no longer! My apologies, friend, but the sense of this thing is too much likened to the terror of Rammas Deluon. I cannot bear its presence.
'But I know now the secret of the stones of Rammas Deluon. It is no spell that grants the statues such power, but a fell spirit of an elder Age, such as those that inhabit the wights which serve Angmar. This stone-heart was prepared to receive such a spirit.
'Perhaps this heart may be made to draw forth such a spirit from another stone. It may be a clue to breaking the will of the watching-stones! Take this stone-heart to the ancient watching-stone which stands near the eastern pass of Ram Dúath to the east of here, not far from Bail Róva, a fortress of the Angmarim.'
The ancient watching-stone is near the eastern pass of Ram Dúath, near Bail Róva, east of Aughaire.
Corunir believes that the stone-heart may be able to draw forth the fell spirit from another watching-stone and has asked you to test his theory upon an ancient watching-stone which guards the passes of Ram Dúath.
Corunir is at the Hillman-village of Aughaire, west of Bail Róva.
With the spirit of the ancient watching-stone defeated, you should return to Corunir with the news of hope.