Final answer:
Elizabeth Proctor fired Abigail Williams after discovering that Abigail had an affair with her husband, John Proctor, a major plot point in Arthur Miller's 'The Crucible'.
Step-by-step explanation:
Elizabeth Proctor fired Abigail Williams from her job because Elizabeth suspected and later confirmed that Abigail had an affair with her husband, John Proctor. Abigail's dismissal was due to Elizabeth's discovery of the affair, leading to the breakdown in trust and association between them. This event is a key part of the motivations and background in Arthur Miller's play The Crucible, which explores themes of betrayal, guilt, and reputation within the tumultuous context of the Salem witch trials. Elizabeth's decision to fire Abigail set in motion a series of accusations and vendettas that amplify the hysteria surrounding witchcraft in Salem.