Fallout 4: Far Harbor – Institute & Brotherhood Faction Endings

On PC, PS4 & Xbox One: Check out these two extra conclusions to the main quests of Far Harbor.


Bring peace to the irradiated islands of Fallout 4: Far Harbor with these alternate faction endings. Most of the expansion’s story takes place on a secluded area off the coast of Maine, but these extra quests take the Sole Survivor back to the Commonwealth. Joining either the Brotherhood of Steel or the Institute puts you on Acadia’s trail, and both quests lead to the utter destruction of one (sorta) peaceful synth settlement. If you feel like being cruel in a cruel world, these two faction-specific ending scenarios are for you.

For those speeding through Far Harbor, be aware that both of these quests are available even after your bring “peace” to the island, in whatever form that takes, so long as you side with DiMA and Acadia. These quests will always be open to take if you’re curious, and you can always save your game before proceeding if murdering basically innocent robots isn’t your thing. Keep reading to get all the info you need to get started, and let us know which ending you picked in the comments.

If you’re a true survivor, check out Gameranx’s massive list of guides, how-to’s, secret locations, and everything else a fresh Vault 111 escapee needs to thrive on the Fallout 4 Ultimate Commonwealth Guide.

Institute & Brotherhood Faction Endings

Not all of Far Harbor’s missions are acquired on the island. Two very specific jobs are available from two very unfriendly factions — the Brotherhood of Steel and the Institute.

Both faction quests will end any progress you’ve made with Acadia’s Synths or DiMA, so continue at your own risk. Here’s how to activate both quests.

Search and Destroy Quest:

To activate this quest, you must be a member of The Brotherhood of Steel.

  • Where to Start the Quest: The Prydwen – Lancer Captain Kells
    • After meeting with DiMA and learning the location of Acadia, tell DiMA that you are a member of the Brotherhood of Steel.
    • Return to the Commonwealth and return to the Prydwen. Talk to Lancer Captain Kells in the airship control room. It’s found just as you enter the airship interior, then take the steps down to the room beneath the viewing deck.
    • Tell Lancer Captain Kells about Acadia. Give him enough info and he’ll send troops to the island.
    • Meet the squad on the western side of the island. Talk to them, and then plan your attack — the synths of Acadia will now be hostile to you and attack on sight.
    • The Brotherhood squad travels in real-time, so you might have to wait before they reach Acadia if you fast travel.
    • Now with the Brotherhood’s help, you can storm Acadia and wipe out the synths. They don’t stand a chance against Power Armor.

That’s all it takes to put an end to DiMA’s refuge. It doesn’t exactly feel great wiping out a bunch  of defenseless Synths, but that’s one of the options available.

Forbidden Knowledge Quest:

To activate this quest, you must be a member of The Institute.

  • Where to Start the Quest: The Institute – William Moseley
    • During your meeting with DiMA in Acadia, tell the Synth that you work for the Institute.
    • Return to the Institute in the Commonwealth, and track down a new character — William Moseley — in the Advanced Systems area of the facility. He’s wearing a full clean suit. Tell him about Acadia and he’ll put together a team to solve the problem.
    • Back on the Island, you’ll find a new relay station and several synths guarding Moseley. Tell him to start the attack to begin the raid. The synths in Acadia become hostile, and will attack if you try to return.
    • The Synths and Coursers will now run across the island and begin their attack. They move in real-time, so wait for them to catch up if you fast travel.
    • Clear the area and talk to William Moseley once Acadia is wiped out to complete the quest.

When the quest is over, William and the defeated Synths will relay back to the Institute for repairs, removing their bodies so you won’t get a chance to loot them after speaking with William. Take everything you need before completing the quest.

Need more Fallout 4: Far Harbor locations, collectibles, and info? Check out the rest of our DLC guides on Gameranx: