The settler will point the Sole Survivor to the raider hideout and ask that they are eliminated for the safety of the settlement.
To proceed with the quest the Sole Survivor must travel to the settlement and talk to their leader, who will give the details: a large group of raiders has been harassing the settlement and causing trouble. Preston will ask the Sole Survivor to travel to the settlement and help them out, hoping that the settlers will choose to support the Minutemen in return. After the Sole Survivor agrees, Preston will tell them about a nearby settlement that has been having trouble with raiders. Upon returning to Sanctuary Hills at the end of When Freedom Calls, Preston Garvey will approach the Sole Survivor and ask them to help rebuild the Minutemen.