In 1911, a widow with two children leaves New York City for territorial Arizona and becomes a ranch hand and later gets herself elected sheriff. A gambler and a rancher become rivals for her affections.

A detective questions baby-sitter Lottie Slocum about the murder of Clara Nash, for whom Lottie had been working. Lottie exasperates the detective by her aimless chatter and her undisguised excitement. After the detective leaves, she tells a friend about the night of the murder. Lottie disliked Clara, who was separated from her husband and was seeing another man. Lottie is so vocal in her disapproval of Clara, and in her affection for Mr. Nash, that her friend wonders whether Lottie was somehow involved. Later, Lottie is threatened by the dead woman's boyfriend. She herself hopes that the situation will give her an opportunity to get closer to Mr. Nash.

From the moment she glimpses her idol at the stage door, Eve Harrington is determined to take the reins of power away from the great actress Margo Channing. Eve maneuvers her way into Margo's Broadway role, becomes a sensation and even causes turmoil in the lives of Margo's director boyfriend, her playwright and his wife. Only the cynical drama critic sees through Eve, admiring her audacity and perfect pattern of deceit.