Moira Brown is a resident of Megaton in the game Fallout 3. As the owner of Craterside Supply, Megaton's general store, she requests that the player help her with field research for a Wasteland survival guide she's writing.
If the player blows up Megaton using the nuclear bomb the city is built around, Moira will be the sole survivor. However, her proximity to the blast leaves her thoroughly radiated to the point that she becomes a ghoul. Moira's trusting nature is such that she simply will not believe the player if they admit that they were responsible for the destruction of the town, and the Survival Guide quest line can still be completed. After her first encounter with the player in ghoul form, Moira moves to Underworld, the ghoul settlement.