He will give you Cull the Drudges, a list of Drudges he wants culled from the local area. This list includes killing 100 Drudge Lurkers.
Drudge Lurkers can be found in a variety of places. The Drudge Fort west of Cragstone has some that spawn outside the fort, along with Drudge Stalkers and Drudge Raveners which also have kill tasks. However, there are Drudge Balloons in the area which can be deadly. There are also several dungeons which have Drudge Lurkers and can be more consistent than searching the landscape.
Return to Jarvis Hammerstone when you have completed the Drudge Lurker task for a title and experience reward.
Jarvis Hammerstone tells you, "The Drudge raids have lessened since you brave souls have started defending the town."
Jarvis lowers his voice to a whisper.
Jarvis Hammerstone tells you, "I don't know what good the Royal Guard are, just standing around and making plans! They say the defense of Cragstone isn't under their charter. Pshaa! They can stuff there rules!"
Jarvis Hammerstone tells you, "The Healer, Avalenne, says she can see the Drudges building some sort of fortification to the West of town. Looks like they're still following that "Plan" of theirs that we uncovered. After all the trouble they caused recently, I don't relish the idea of having those thieving parasites as neighbors."
Jarvis Hammerstone tells you, "The Cragstone Elders have charged me with the task of getting rid of the drudges and I will reward you well if you can discover what they're doing in that fort of theirs."
Jarvis Hammerstone tells you, "In the meantime I need to rid the surrounding area of some of these Drudges. There seem to be more every day. Take this and come back to me when you have completed any of the tasks listed."
Jarvis Hammerstone gives you Cull the Drudges.
Jarvis Hammerstone tells you, "Come see me when you have killed all 100 Drudge Lurkers."
Notes
In the Shattered Lines event, the drudges retreated from the main town of Cragstone to their fort just west of town.
