The quest requires you to defeat a Jatu army that ventured in the Noldor forest. This army will have a blue color unlike other Jatu armies, called Marauding Jatu Army, and it will not attack anyone, nor be attacked by anyone (not even the Noldor). This means that you will have to face the army alone.
If you succeed, you will be allowed access to Elacrai, the hidden home of the Noldor, whilst you have over 30 relation points with them. In Elacrai there are 4 special npcs, as well as the Noldor Tournament.