Witch Hunt

Witch Hunt is a side quest in the Fallout 4 add-on Far Harbor.

Detailed walkthrough
This quest is provided as part of the optional objective "Help the High Confessor" under What Atom Requires. Asking him if there's any work to be done will result in him demanding the Sole Survivor investigate a member of the cult for disloyalty, handing over the High Confessor's note. Reading the note reveals this person as Sister Aubert, at which point Edgar's note becomes available tucked under her bunk in the Vessel. Reading this note leads to the footlocker key in the Nucleus near the exit to the Island, which opens Edgar and Aubert's footlocker. Inside is Aubert's note, which denounces the High Confessor and accuses him of having Edgar killed.

At this point the player character can either bring the note directly to the High Confessor, thus concluding the quest, receiving the Inquisitor's cowl and presumably getting Aubert killed for her disloyalty, or they can confront Aubert. If the latter option is taken, she will beg for the note to be handed over so she can destroy it. The player character can tell her to run, ask for payment (about 95 caps), hand the note over or withhold the decision.

When talking to the High Confessor, the player character has the option to lie (medium Charisma check) that Aubert is loyal, thus receiving the Inquisitor's cowl without condemning her. If the check fails and the note was given back to her, the only option is to lie and say that no proof was found. The High Confessor is disappointed with this result and keeps the cowl, but the quest concludes.

Companion reactions

 * Nick Valentine dislikes accepting this quest and likes refusing it. If Sister Aubert is successfully persuaded to speak poorly of Tektus and this is mentioned, he will dislike that as well.
 * When confronting Sister Aubert with her note, Nick likes telling her to run, dislikes asking for a payoff and loves giving the note back to her.
 * Nick likes completing the quest by lying to Tektus, whether saying that no proof was turned up or convincing him that Aubert is loyal. He hates completing the quest by handing over the note.
 * Hancock dislikes accepting the quest with the "Consider it done" dialog option, but likes giving Aubert's note back or telling her to run. Hancock also likes ending the quest by lying and telling Tektus that Aubert is loyal.
 * Curie dislikes completing the quest by handing over the note.
 * Curie likes completing the quest by handing the note to Sister Aubert and then lying to High Confessor Tektus with speech check.