You have been encouraged to learn the lay of the waste that is East Angmar, so you may better find your way to Gath Forthnír when needed.
'Welcome to Gath Forthnír, ${PLAYER}. This is a grim and cheerless place, but we do what we must to stand against the shadows that press us.
'You seek to learn the secret paths to Gath Forthnír? I could speak to you all day, and if you did not possess enough skill as a hunter, it would not matter -- anything I could teach you would flow over you like water and mean nothing.
'You must prove to me that you have the skill, ${PLAYER}. When last I scouted the eastern lands of Angmar, I let fall a brooch I carried; I did not realize it was missing until I returned here. If you can follow my trail, you might find the brooch where I dropped it. If you are able to do this, return the brooch to me, and I will teach you what I know.'
Maerchiniath's brooch is somewhere in East Angmar.
The Ranger Maerchiniath has agreed to teach you how to find secret paths through East Angmar if you can follow the trail he took when he lost his brooch and bring it back to him.
Maerchiniath is at the hidden camp of Gath Forthnír, in East Angmar.
You have recovered the fallen brooch and should return it now to Maerchiniath.