The following story can be experienced the starting the quest "For the Love of Nature" at The Red Pass in the Lone-lands.
Glorfindel made his way to the Last Bridge from Rivendell. He was one of the mighty first-born and his deeds were often sung by the remaining Elves of Middle-earth. He had been one of the few who the Valar sent back to Middle-earth from Valinor, and it was here that his final purpose lay before him. Glorfindel was to find and protect Frodo Baggins, who carried the weapon of the enemy, at all costs. As he reached the bridge at Lord Elrond's behest, he found Black Riders upon it led by the Witch-King of Angmar. This had not been the first time Glorfindel faced the Witch-king. He had claimed victory over the Nazgûl during the Battle of Fornost, which broke the Witch-King's hold upon Eriador many years ago. He drew his sword and rode towards the Nazgûl. Glorfindel's angelic presence radiated and blinded the Nazgûl. They fled in fear of him, scattering into the Trollshaws. The bridge, at least temporarily, had been made safe. He pulled an emerald beryl from his belongings and placed it upon the bridge. Gandalf would know it was a sign from Glorfindel that the bridge had been made safe. With no sign of the halfing, Glorfindel turned back to the road in search of him...
Radagast had been very clear with the heroes; nothing in Agamaur could be redeemed without the aid of the Red-maid. Before they could storm the fortress of Garth Agarwen, the heroes would have to cleanse the Red Swamp of its taint.
The heroes faced many evils within Agamaur. Wights, Darkwater, and even Hillmen of Rhudaur, who now served the Red-maid. Dannasan, who was oathsworn to protect the Red-maid, told of her altar where she would calm the waters many centuries ago. Before they could heal her pain, they would first have to bring innocence and beauty back to her sanctum.
The heroes reached her altar and acquired a sample of the water within it. Radagast the Brown told of the Red-maid's sisters who embodied every river within Middle Earth and whose water could purify the sample. By great chance, Radagast had acquired water from the Withywindle in the Old Forest on his journey towards the Lone-lands. He produced a vial of water that, upon pouring into the sample, purified the Red-maids red water to a clear, beautiful color. Radagast asked the heroes in return to bring an end to Grimbark, an ancient tree whose roots corrupted the land, bringing death to all peaceful creatures around it.
With the forces of evil outside Garth Agarwen thinned and their preparations complete, the time had come for the heroes to siege Garth Agarwen. The heroes tasks were three-fold; End Grimbark’s spreading corruption, Defeat Ivar the Blood-hand, and cleanse the evil from the Red-maid.
The heroes first infiltrated the Arboretum where Grimbark stood. The passage to the great tree was treacherous. Darkwaters roamed the rivers that passed through the Arboretum and all the life that Grimbark had corrupted had drawn undead to it. Through great peril, the heroes reached Grimbark’s clearing. The great tree, while unable to move, brought the very wildlife around it against them. Upon it’s defeat, the heroes recovered one of Grimbark’s seeds in hopes that Radagast may be able to regrow the tree in time.
The heroes next made their way to the Barrows where Ivar the Blood-hand dwelled. Men of Rhudaur, who had sworn allegiance to the Witch-King of Angmar centuries before, protected the Barrows’ entrance. The heroes fought through the Hillmen to find the once-great Barrows of ancient Rhudaur warriors now defiled and, in their place, stood twisted Wights.
Shockingly, the heroes came upon Sara Oakheart being ambushed by undead while looking for Ivar. This had been the second time each of the heroes had encountered Sara and her presence raised further questions. There was no time for questions however, so the heroes swiftly helped her out of the Barrows.
Sara grabbed an ancient scroll on her way out. This had, unusually, been here purpose. Before the heroes could speak any further of it, she retreated out of the Barrows. With her safety assured, the time had come to defeat Ivar atop the central barrow.
The heroes moved swiftly and engaged the necromancer. The battle was hard-fought but the heroes came out victorious. With Ivar defeated and Grimbark destroyed, the heroes made for the Red-maid's spring to free her from the clutches of evil.
Again, the heroes found scores of Men of Rhudaur and Wights. The heroes fought until they reached the entrance to the Red-maid's spring. Vatar, a wight-lord, imparted on the heroes a vision of the past. The oathsworn to Iarwain Ben-adar had come once before to reclaim the Red-maid but had failed.
The heroes would not be discouraged, however, and defeated Vatar and gained entrance into the spring. There, they finally encountered The Red-maid, corrupted and fearsome. Her disciples, Men of Rhudaur, kneeled before her.
The heroes fought valiantly against her and her devoted. They held their own until the heroes were able to drop her cleansed water upon the spring. Miraculously, the Red-maid was restored to her true self; Naruhel the River-Sister. She grieved over the malice she had wrought upon the land and it’s people but she was also driven with purpose. She thanked the heroes for everything they had done, and vowed to restore the land to it’s former glory.
The heroes returned victorious to Radagast. He was delighted to learn the land would be restored and it's creatures saved. With Ivar defeated, Radagast revealed the history of the Gaunt-lords. In ages past, Morgoth twisted enslaved Men and instilled them with fell spirits. These became the gaunt-men, but among them he selected five who would bear unimaginable power in mockery of the five Wizards. Ivar was, in fact, made in mockery of Radagast, which is what drove Radagast to see his end.
The heroes exited the wizard's tower and were stopped by an Eglain who came bearing a letter. Candaith, the ranger, summoned the heroes back to his camp. Fires in the North had been spotted and the rangers now called for aid...
Further Reading: Fires in the North