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The Nucleus (formerly Mount Desert Island Naval Facility) is a pre-War United States Navy submarine base, and after DiMA made it his home, allowed the Church of the Children of Atom to settle the location. In return for the new home and center of worship,[1] they agreed to protect his old memories from being accessed.


The Nucleus, or rather the Mount Desert Island Naval Facility, is a former United States Navy submarine pen, still housing the derelict USS Democracy in its dry dock. While there for repairs and refitting[2] the submarine's reactor was sabotaged by the captain, Arnold Wabash. With the Democracy's nuclear reactor leaking radiation, its crew and captain were recalled while hazmat teams worked around the clock to clean the facility and make the submersible usable again. However, the process would take weeks to complete. Admiral Edward Grath suspected foul play and informed Captain Wabash that he would file the court-martial personally if he was responsible.[3] The personnel of the base would survive the nuclear bombardment, and so would the admiral,[4] but not the captain.[5]

Following the Great War, the facility lay idle, its radiation keeping people away, until around 2178. After DiMA landed on the Island, he found the facility and made it his home. Sometime later, Faraday joined DiMA, and, after the Church of the Children of Atom was exiled from Far Harbor, the congregation led by Confessor Martin were guided to the facility by the Mother of the Fog.[6][7][8] Afterward, DiMA departed to found Acadia, leaving the base in safe hands.[9] While there, however, DiMA used the base's computers to expand his limited storage capacity, offloading the oldest memories into the pen's data banks.[10] For their new home, Confessor Martin agreed to guard his memories.


The facility exterior, made almost entirely of concrete, is built into the side of a mountain. Upon entry, there are two doors on the left that each lead to a locker room. If one continues down the hallway, they will arrive at the base. On the right is the Vessel, a pre-War submarine.

Continuing forward through a wooden shack, there is a wooden ramp up. If one goes up, they will arrive at the shopfront of Sister Mai, and a little bit further is the shopfront of the Archemist. Turning left and going up the stairs leads to Brother Kane and a power armor station. Going further up the stairs will lead to the entrance to the Nucleus Command Center, guarded by a zealot.

Going straight from the Archemist's shopfront, there is a staircase that goes up on the right and a staircase that goes down on the left. The staircase on the right goes through multiple wooden shacks to end up at the entrance to the Vessel. The staircase down leads to Zealot Ware. From Zealot Ware, there is another staircase on the right that leads to the bottom of the Vessel and a ramp. The ramp also leads to the entrance to the Vessel.


Notable loot

Related quests


When visiting while wearing power armor, the Children may comment about how Atom powers the suit.


The Nucleus appears only in the Fallout 4 add-on Far Harbor.



  1. Far Harbor loading screens: "The Nucleus is home to the Children of Atom. It is built out of a prewar nuclear submarine base that the Children have converted into a town and center of worship."
  2. The Nucleus terminal entries; Captain Wabash's terminal, SUBJ: VR System
  3. The Nucleus terminal entries; Captain Wabash's terminal, SUBJ: Containment Leak
  4. The Nucleus terminal entries; Captain Wabash's terminal, SUBJ: Where are you
  5. Safe room security tape
  6. The Sole Survivor: "What can you tell me about the Mother of the Fog?"
    Tektus: "The Mother is one of Atom's most revered messengers. Many years ago, when we were driven from Far Harbor, it was she who guided us through the wilds to this sanctuary. We might all have been lost if it wasn't for her. You should be honored she found you so... interesting."
    (Tektus' dialogue)
  7. The Sole Survivor: "How is it you came to this place?"
    Tektus: "We were guided here, many years ago, after our exile from Far Harbor. The first of us, my predecessor Martin and I, had come north at the behest of Atom's great prophet, Confessor Cromwell... ...from a small refuge in the Capital Wastes. When we arrived on the island, we found a few souls receptive to Atom's message. Anna... the Archemist... was formerly Far Harbor's doctor before she found the Light. But most... they thought us a menace. We were chased from the town, driven into the wilds. Barely escaped with our lives. Some of us were... never the same. It was only thanks to the grace of Atom that we survived... and finally found a place that we could call home."
    (Tektus' dialogue)
  8. Brian Richter: "Hmph. You're back. More than I expected. Did Atom reveal something to you?"
    The Sole Survivor: "I drank from the spring and a woman led me to this icon. Does this mean something?"
    Brian Richter: "A woman? Led you to that icon? What woman? What did you see?"
    The Sole Survivor: "Is there something special about this thing?"
    Brian Richter: "I think it may be a message from someone very important. So I need you tell me what you saw."
    The Sole Survivor: "It was... otherwordly. The woman, she was like a living shadow, cloaked in mist."
    Brian Richter: "Atom above. You really did see her. The Mother of the Fog. The Mother is a messenger from Atom. Acts as a guide to those important to His plans and the future of this family. She's the one who led the first of us to this place. And if she revealed herself to you... then I'd say the path He's lain for you is clear. If you are prepared to take the next step, then I believe there is a place for you among Atom's children."
    The Sole Survivor: "So what exactly happened to me at the spring?"
    Brian Richter: "Seems Atom granted you a vision. Only those deemed worthy of joining the Children have them... and live. But for some rare souls, he sends... more. A messenger. Or in your case, the Mother."
    The Sole Survivor: "So was the Mother real?"
    Brian Richter: "Most believe she's some sort of spirit, a creature of the wilds, though a few claim she's just an old hermit. Regardless, our family wouldn't be here without her. If she figured in your vision... well, there are few signs clearer you're meant to be one of us."
    (Richter's dialogue)
  9. The Sole Survivor: "The Children of Atom on this island. You were helping them?"
    DiMA: "Yes. I know their faith in radiation as a type of god is a bit... different, but who am I to judge? I was using a submarine base as a home when Martin and his followers stumbled inside. They had been cast out of Far Harbor for their beliefs. When I left to found Acadia, I knew the base would be in safe hands. They needed a home. A place to belong, just like I did. But now Martin is gone, and his successor, Tektus, wants to finally end the feud with Far Harbor, by letting the Fog swallow them."
    (DiMA's dialogue)
  10. The Sole Survivor: "You left your memories behind? How does that work?"
    DiMA: "As a prototype synth, my... raw data capacity is limited. I began using computer banks to expand. To give me room to ponder. See new things. I had to leave some of my earliest memories behind when I left the sub base to the Children of Atom. I thought they were safe."
    (DiMA's dialogue)