'While both you and I have seen five Nazgûl, their true number is nine. Before I can take my charges beyond Bree, I must know where the other four are hiding.
'Would you travel to the west and speak to Lenglinn? I sent him to Buckland to watch over a particular hobbit, but it seems that Mr. -- Underhill and his friends decided to take a different path and are now here under my protection. Still, Lenglinn may know the whereabouts of the remaining Nazgûl.
'He camps on a rise just north of the Buckland Gate and may have seen something that will aid me. You must hurry. I cannot afford to delay here overly long.'
While you were away investigating the Blackwold brigands, five Nazgûl attacked The Prancing Pony in search of four travellers from the Shire, which Strider had under his protection. Strider has told you that there are a total of nine Riders, and that he must know the location of the other four.
Strider has asked that you speak with Lenglinn, another Ranger, and learn if he has seen any other Nazg'l passing out of the Shire.
'Aragorn has sent aid! Nazgul, four more, were in Buckland. They rode swiftly to the east, upon black steeds. I was foolish enough to stand in their way, and they ran me down.
'I will heal in time, but the Riders have left a threat in their wake that must be dealt with. I must ask for your help.'
This is just like the previous quest, just talk to and click finish. Lenglinn is just up the hill from the creban just off the road between Bree and Buckland, at 30.1S, 61.3W; just North of the Craban birds.