Antoinetta Marie is a Breton member of the Dark Brotherhood who can be found at the Dark Brotherhood Sanctuary located in Cheydinhal. She wears the basic Dark Brotherhood armor, which cannot be equipped when taken.
Although she seems to be the most "innocent" member of the Sanctuary, her bloodthirst is obvious in dialogues. She dreams of taking over Ocheeva's position in the Sanctuary someday.
It is also hinted she may have been heavily abused by prison guards. She refers to them as "strong and cruel, so very cruel" if one ask her for advice on the contract Scheduled For Execution. If asking her this when her disposition is below 30, she will say "I can only hope the prison guards do to you what they did to me. You will know the true definition of the word 'horror.'"
- Antoinetta Marie is a reference to Marie Antoinette, a former queen of France who was executed at the age of 37, mostly based on accusations that were untrue.
- The player can find a note in the room of Ocheeva chest from Vicente Valtieri about his disease to the garlic as she had done a meal with garlic in it.
- Out of all the members, she is the most friendly during the hero's first meeting.
- She may be in a relationship with Mathieu Bellamont as she receives a letter, from him, (from anonymous) to leave the sanctuary as he knows about the purifacation that is about to occur.
- The Elder Scrolls IV: Oblivion (First appearance)