You found a note left by Laerdan indicating that he has left Rivendell with the intent of bringing the shards of Narchuil to Amarthiel.
'${PLAYER}, it seems that Amarthiel's tormentors succeeded in breaking Laerdan's mind. He has left Rivendell and seeks to bring the shards of Narchuil to Amarthiel in the vain hope of restoring her mind to Narmeleth.
'Time is of the essence! We must learn quickly how far ahead Laerdan has gone. We must try to overtake him before he can complete his purpose.
'Speak with Ladrochan, the stable-master, at the stables to the west of here. He will surely have seen Laerdan.'
Ladrochan, the stable-master, can be found in the stables of Rivendell, west of the Last Homely House.
Elrond has told you to speak with Ladrochan and learn how long ago Laerdan left Rivendell.
Elrond is in his library in the Last Homely House of Rivendell, to the east of the stable.
Ladrochan told you that Laerdan had left Rivendell two days ago. You should return to Elrond with this news at once.