Arohir of Esteldín has bade you seek the hidden camp of Gath Forthnír in the far north, somewhere east of the gates of Carn Dûm, and once there to speak with Annábla.
'I have heard rumour that a hidden camp exists near unto the very gates of Carn Dûm in the far north where brave heroes gather to contest the power of Angmar itself.
'I cannot say precisely where Gath Forthnír -- as it is called -- lies, but should you find this place, speak with one called Annábla, and she will tell you more of their purpose.'