Find the Treasures of Jamaica Plain

Find the treasures of Jamaica Plain is a miscellaneous quest in Fallout 4.

Detailed walkthrough
Find the Treasures of Jamaica Plain is a miscellaneous quest triggered by finding Hadrian's body, which appears randomly throughout The Commonwealth, and listening to Hadrian's invitation located in his inventory. It can also be triggered by finding and reading a Jamaica Plain flyer, found in various places throughout The Commonwealth. Alternatively, one can simply locate Jamaica Plain and enter the town hall's basement without having actually triggered the quest.

Upon discovering Jamaica Plain, the player will need to locate the Jamaica Plain Town Hall basement. The town hall is found in the southern portion of the town and is easily visible as it's one of the biggest and most distinct buildings in the area. The basement is to the left of the main entrance and down a set of stairs.

Jamaica Plain itself is swarming with feral ghouls. It's highly advised to come here ready to face several of them at once. Clearing the town of feral ghouls is not a prerequisite of entering the basement, however.

In the basement, the player will be able to quickly make their way to a small hall filled with laser trip wires. Activating one of them will cause several turrets located near the end of the hall to begin firing in their defense of the "treasures" located within. These trip wires can be disarmed one by one, each giving the player steel and fiber optics. They can also be disarmed with the computer panel in front of the hall by using the Jamaica Plain mayor's password, which is found on a dead body inside the church across from the town hall. To obtain it, one would need to access the church through the roof as the ground entrance is chained from the inside.

Alternatively, the player has the option to pick the lock on a Master-locked door to bypass the tripwires. Once they go through the short corridor that follows, the door to the treasure room is locked by a Novice terminal in the center of the room. If the player fails to hack the terminal on the first try, the two Protectrons in the room will activate and become hostile.

Once through the door guarded by the trip wires, traveling trough the remainder of the basement and a few more doors (or the shortcut) will lead to the "treasure" of Jamaica Plain, containing the 2076 World Series baseball bat and many unique pre-war items not found elsewhere in the game. There are also some holotapes on the table immediately within the room, such as the Treasures inventory holotape, which lists items that are found in the treasure vault and the reasons for it existing. However, given the passage of time most of the artifacts have suffered heavy degradation.

Bugs

 * The turrets may spontaneously activate after disarming a small number of the laser tripwires, even if none of them have been tripped. This usually results in the player's immediate death.