Sharkey's Men have holed up in a camp they call the Brigands' Watch. Grimbriar wants you to go there and gather information about Sharkey and his plans.
'With your help we draw ever closer to shutting out this upstart, Sharkey. We are closing in more and more on his location and the size of his force.
'We now know that the Brigands' Watch, to the west of here in the foothills of Bree-land, is a staging ground for future assaults. The brigands' captain hands out orders from Sharkey himself to his lieutenants.
'Likely they are kept somewhere safe: a lockbox or even on his person. We need those orders. Head to the Brigands' Watch and get those orders.'
The Brigands' Watch sits on a hill north of Adso's camp, and directly west of Grimbriar's Post. Watcher Grimbriar is at his post near the cross-roads of Bree.
Grimbriar has instructed you to search the tent of the brigand-captain at the Brigands' Watch to find any correspondence from Sharkey that may divulge information about his plans.