Lheu Brenin wants you to speak with the emissary of Isengard he is holding captive in the cave behind Tûr Morva.
'You know of the emissary Saruman sent to us to force our cooperation? He is being kept under watch in the prison-cave. He has not told us anything of use yet, but perhaps you can inspire him to speak.
'Go into the prison-cave and speak to the guard Nai. He will allow you to press the captive for information. Return and tell me if the captive has anything useful to say. If he does not, perhaps his usefulness is at an end, and Nai can be given something else to do.
'The prison-caves are to the south. Follow the path and you will see the entrance among the ruins on your left-hand side, in the cliff.'
Nai is guarding the captive emissary of Isengard in the prison-cave, south of Lheu Brenin and in the wall of the cliff to your left.
Lheu Brenin has asked you to press the captive for information. First, you should speak to the guard Nai outside his cell.
Nai has given you permission to enter the cell with Dondhreg to see if you can get any information from the captive emissary.
You have spoken with Dondhreg, but if there was anything valuable in his words it will be up to Lheu Brenin to discern it.