Moira Brown

 is the eccentric, sometimes inappropriately cheerful, and possibly clinically insane (according to her logs and conversations) owner of Craterside Supply in Megaton in 2277.

Background
Moira was born in 2253 in the trading community of Canterbury Commons but lives in Megaton in 2277.

Daily schedule
Moira is the owner of Craterside Supply. She spends the day sweeping and trading as well as conducting odd experiments. She opens the store at 8:00am and closes at 8:00pm. She lives at the store and thus never leaves. The only time she will leave is if Megaton is destroyed. She will then make her way to Underworld.

The Wasteland Survival Guide
Moira wants you to do some dangerous research for a book she is writing entitled The Wasteland Survival Guide.

At multiple points of this quest line you can attempt to convince Moira that writing the guide is pointless and that she should center on more important things. If you do persuade her to stop writing though, you will gain negative karma, and the Dream Crusher perk which causes anyone attacking you to have 50% less chance of scoring a critical hit. It also causes Moira's mood to mellow out and focus on her store, thus giving the player a discount on all items she sells (however this discount is negated if you enter the buy/sell screen through the house upgrade speech option). Her repair skill increases from 52% to 72% as well.

Destruction of Megaton
If the player character helps Mr. Burke detonate Megaton's nuclear bomb in The Power of the Atom quest, Moira survives the blast as she was outside of town researching for her guide at the time. She even remarks on how an experiment of hers, a Nuka-Psycho hybrid substance, might be responsible for the explosion. However, the massive exposure to radiation transforms her into a ghoul. She will then relocate to Underworld. She does not appear to know she's a ghoul at first, but even if the Lone Wanderer points it out, her sorrow is extremely short-lived. Typical for her personality, she optimistically realizes that she's always wanted to run some experiments on ghouls and can now use herself as a subject. Moira will still offer the quest The Wasteland Survival Guide after she becomes a ghoul.

While talking to the Ghoulified Moira for the first time, you can lie and tell her you're not the responsible of the explosion, or tell her you exploded the city to kill her. If you choose this option, the conversation will end, she will turn hostile and flee.

Appearances
appears in Fallout 3

Bugs

 * Occasionally, Moira will not move from the Megaton ruins after the town has been destroyed if you have completed the quest The Wasteland Survival Guide. She will stand in front of Megaton and can only repair. (confirmed on all platforms)
 * If the player kills Moira Brown before destroying Megaton, you will still receive the message saying she has moved to Underworld, and Three Dog will still announce that she can be found there; however, she will still be dead and will not appear there.