Fallout 4 - Mass Fusion - Institute Main Quest [Survival Difficulty] (2024)

12+

The Institute is ready to initiate Phase Three of its long-term plans. Phase Three involves starting a new mass reactor that should resolve the Institute's ongoing power needs. To start the reactor, the Facilities division first needs to obtain a beryllium agitator, a device used to "jump-start" the reactor. Father tells the Sole Survivor to speak with Allie Filmore for the details of that operation.Dr. Filmore explains that the Mass Fusion building in downtown Boston is known to have an agitator on-site, but retrieving it has become problematic due to the Brotherhood of Steel at that location. Allie assumes that the Brotherhood is also looking for the agitator, and she wants to make sure the Institute gets to it first. She also insists on coming, promising not to get in the way but not totally trusting the Sole Survivor with the delicate technology. If one prefers not to have her along, they can tell her flat-out that she isn't coming because she'd just be a liability. She will be insulted but will not accompany the player character.When ready to continue, take the central elevator up to the Relay room. Upon entering the relay, one should get a warning that relaying to the Mass Fusion building will make them a permanent enemy to the Brotherhood of Steel. Continue and the player character will be teleported to the Mass Fusion executive suite.Alternatively, by informing the Brotherhood, Spoils of War will start, and boarding the Vertibird that spawns on the Prydwen will make the Institute hostile. (Tactical Thinking must have been completed before one can continue with this part of the quest.) Every unfinished quest for one of the factions will fail immediately and they will permanently become enemies. This is the breaking point between the Brotherhood of Steel and the Institute.Upon arriving at the Mass Fusion building, there will be Brotherhood faction members present throughout the building. As with other factions, one must fight down through the building, obtaining an Executive keycard and re-routing power to the elevator when it stops. Both the keycard and the laboratory password are located in a desk on the second floor of the first room one enters. The password is used to access the executive lab terminal (also in that first room) which will tell the Sole Survivor exactly where the beryllium agitator is located within the building. For a little more backstory, grab Oslow's office recording on the table beside the terminal. Afterwards, proceed to the executive elevator in the center of the room and proceed down into the building.While riding the elevator down, the player character will be assaulted by Brotherhood members coming out onto each floor. After several floors, they will cut power to the elevator and the player character will get the optional objective to restore power. Power can be restored either by using the development manager's terminal on the first level, or alternatively by flipping the circuit breaker located on the second level. The quest marker only points to the circuit breaker, but either method can be used successfully.On the level with the glass floor, the Mass Fusion labs key is sitting on the desk with the active terminal. The key opens the locked door in the corner, allowing the player character to proceed downward without restoring power to the elevator. On the opposite side of the room with the glass floor, there is a ramp leading up to the next level. Directly across from where the player character comes up, there is an issue of Tesla Science laying on a console. On the other side of the second level, one will find the fuse panel where power can be restored. If the player character is wearing power armor with a jet pack, this is also a good time to get the Freefall Legs, which are located in a safe several levels up from the glass floor.Note: If one stands in the center of the glass floor with your back to the elevator, and look down through the glass, they'll see a couch on a balcony above the large silver statue. On the head of that statue is the Strength bobblehead.If the player character takes the restored elevator down, they'll end up at the ground floor lobby, where there is another elevator that will take them down to the reactor level. If the player character uses the key and drops down instead, they'll end up on the next floor under the glass floor. From there they'll need to fight their way down to the lobby, making sure to grab the Strength bobblehead if they haven't already. If the player character hasn't entered the building prior to this mission, there may be both Gunners and Brotherhood soldiers found on the levels, although usually, the Brotherhood is pretty thorough about killing off the Gunners.When the player character reaches the reactor level itself, they'll need to enter the chamber and remove the beryllium agitator from the reactor. The room is heavy with rads, so much so that drinking the water is instantly fatal.