If you’ve visited the town of Jamaica Plain, by now you’ve probably heard of the town’s intriguing secret: it’s rumored that there is a treasure buried underneath the city, dating back to the pre-War era. So, how do you track down this cache of riches?
First fast travel to your settlement at Jamaica Plain. Head towards the east exit of the settlement and you will see a large church with a red door, which will be closed and chained. Venture around the right side over the windows. The one on the furthest right will allow you to get into the building.
From there, go unchain the front door and pull a few items off the body of a nearby scavenger named Luke Silverhand. He will have on him the Jamaica Plain Mayor’s ID, which you will need to get the treasure. He will also have a Jamaica Plain Flyer, a leaflet advertising the treasure.
After that, take a right after you exit and head north until you find the body of a man named Carl. He will have on him the Jamaica Plain Town Hall Key, another item you will need to obtain the treasure. He will also have a personal log on him with several entries, which you should read before proceeding.
Follow your map marker over to Jamaica Plain Town Hall and head down to the basement. Use the Mayor’s ID at the necessary panel, then deactivate the laser traps until you get to the release door. There are two Protectrons on either side of the entrance to the treasure room, and you will need to hack the terminals and deactivate them before using the main computer terminal to open the door. Once you succeed, proceed through the entrance to retrieve your treasure. There are two holotapes at the location, one of which details the items in the room. Enjoy!