Strewn throughout the lore you discovered in previous efforts for Tobold Leafcutter were stories of a great Cardolan treasure. He believes that two brothers, warriors of Arnor, fought and recovered the treasure and brought it to the Northern Barrow.
'It seems that this may not be the first time that such terror has plagued these lands. The bits of parchment you recovered lead me to believe that two brothers fought to recover a great treasure of Cardolan and brought it here to the northern Barrow-downs.
'The lore-fragments you brought me mention a fortress named Ost Gorthad. The Men of Cardolan took many of those who fell sick to the Plague there. The ruins of that fortress still stand today in the south! It is from here that a terror rose and cursed the brothers for their theft.
'If you are willing, you may seek the treasure or the history of that treasure at the Northern Barrow, not far from here to the east. Perhaps we can learn more about these Men and how to stave this evil from spreading beyond the bounds of the Barrow-downs.'
You may find a chest resting at the Northern Barrow, the northernmost barrow of the Barrow-downs. Tobold Leafcutter waits for you between the Old Forest and Barrow-downs.
Tobold Leafcutter has asked you to search the Northern Barrow for more lore. He hopes that lore from the Men of Cardolan may have survived the long years since the Great Plague in a chest. If you find such lore, you should bring it to Tobold.