The Elves have launched an attack to retake Barad Morlas from the Dunlendings who have invaded Eregion. While the initial attack was successful, a larger force of Dunlendings fell upon the Elves while they were caring for their wounded. Now trapped among the ruins and pinned under assaults from the Dunlendings' siege-engines, the Elves are in desperate need of aid.
While the Elves are skilled warriors capable of easily fending off the Dunlendings' assaults, the siege-engines in the field have them pinned down and are dwindling their numbers. You must take to the field, find the siege-engines, and defeat their crews, buying respite for the Elven defenders.
With his siege-engines out of commission and his assault faltering, the Dunlending commander is leading a final attack against the bridge. He must be stopped.
Having defeated the Dunlendings and routed their forces, you may now use the ancient forge to empower your infused sapphire with the blessings of the Elves.