Fallout Wiki
Fallout Wiki

Forbidden Knowledge is a quest in the Fallout 4 add-on Far Harbor.

Quick walkthrough

Far Harbor side quest: Forbidden Knowledge
Inform Dr. Moseley of the escaped synths at Acadia.
Return to Acadia and talk to Mosley to begin the attack.
Subdue the synths.
Return to Mosley and let the synths be teleported back to the Institute.
Reward: 500+ XP

Detailed walkthrough

Upon the discovery of Acadia and while allied with the Institute, the Sole Survivor has the option to inform the Institute of the existence of the escaped synths in this location. The Institute will then send a team to Acadia to subdue and capture the escaped synths. The player character needs to speak to Dr. Moseley to begin the raid of Acadia. After a brief battle, all the escaped synths are teleported to the Institute.

Quest stages

Quest stages
StageStatusDescriptionLog Entry
100 Speak to Dr. Moseley.After informing the Institute about the existence of Acadia, a team was sent to the island to deal with the situation. I need to check in with Doctor Moseley, and let him know it's time to reclaim the escaped synths.
200 Subdue the synths in AcadiaAfter informing the Institute about the existence of Acadia, a team was sent to the island to deal with the situation. It's time to reclaim the escaped synths; once I arrive at Acadia Institute forces will join me.
400 Speak to Doctor MoseleyAll of the escaped synths in Acadia have been successfully subdued by Institute forces. I need to check in with Doctor Moseley.
500Quest finishedQuest CompletedAfter being informed of Acadia's existence, a team from the Institute has successfully re-captured all of the escaped synths living there. They will be re-purposed and put to work once more.
1000Quest failedQuest Failed


  • Completing this quest can fail Close to Home, as Kasumi Nakano will be captured by the Institute if she is still in Acadia.
  • Completing this quest before completing Reformation will remove the possibility of a peaceful ending to the war between Far Harbor and Children of Atom.
  • As long as Dr. Moseley is not spoken to, Acadia will not become hostile and any Acadia-related quests can still be completed, including Close to Home.
  • The game is not actually teleporting synths from Acadia to the Institute or elsewhere, it is just animation. They all stay in Acadia, disabled.
  • All Institute personnel and subdued synths are instantly teleported, but dead bodies remain where they fell.


  • PCPC This quest appears ill-suited to the perk Intimidation, using it during the quest results in several bugs: [verified]
    • PCPC First, if used on any synth refugees, if successful they become a lower priority for the synth troopers, who will attack the ones currently firing on them first. Once those are killed, they will then open fire on the synth refugees that have already surrendered, and keep firing until they are dead.
    • PCPC For named characters, Intimidation works on some of them but not others, but the effect is the same - when finished with those actively fighting against them, they open fire on the surrendered named characters until they go down.
    • PCPC Despite being on the player's side, Intimidation works against the attacking synths as well. If Intimidation is used against William Moseley, he will briefly raise his hands as if to surrender, then begin running away to flee the battlefield as he no longer has a weapon.
  • PCPC Playstation 4Playstation 4 Xbox OneXbox One The synths will not teleport back and will follow the player character outside.[verified]
  • Playstation 4Playstation 4 Upon talking to William Moseley about the synth refugees, he will not acknowledge the Sole Survivor and will continue what he is doing.[verified]
  • Playstation 4Playstation 4 Xbox OneXbox One After killing all synths in Acadia during the quest stage "Subdue the synths in Acadia," the quest will not move on to the next stage.[verified]
    • This can be fixed by exiting Acadia and killing them once again when they spawn outside. Then, furthermore, entering once again and repeating this process until the quest stage moves on.
    • Alternatively, wait for Moseley and the assisting synth troopers to enter the observatory before charging in. Make sure that Aster is the last synth downed in combat.