Joe wants the player character to find any trace of his grandfather Brent, a member of the Minutemen up until his disappearance.
After this, normal vendor dialogue will be available, through which the player character can request information about the job. If he has never been spoken to beforehand, he will rope the Sole Survivor into a dialogue trying to talk his son out of joining the Railroad. The quest is obtained from Joe Savoldi, the owner of the bar in Bunker Hill, who will most likely be at his bar/motel on the west side.
