Mourning Becomes Electra by Eugene O'Neill

it is late spring afternoon in front of the Mannon house. The master of the house, Brigadier-General Ezra Mannon, is soon to return from war.

        Lavinia, Ezra's severe daughter, has just come, like her mother Christine, from a trip to New York. Seth, the gardener, takes the anguished girl aside. He needs to warn her against her would-be beau, Captain Brant. Before Seth can continue, however, Lavinia's suitor Peter and his sister Hazel, arrive. Lavinia stiffens. If Peter is proposing to her again, he must realize that she cannot marry anyone because Father needs her.

      Lavinia asks Seth to resume his story. Seth asks if she has not noticed that Brant looks just like her all the other male Mannons. He believes that Brant is the child of David Mannon and Marie Brantôme, a Canuck nurse, a couple expelled from the house for fear of public disgrace.

    Suddenly Brant himself enters from the drive. Calculatingly Lavinia derides the memory of Brant's mother. Brant explodes and reveals his heritage. Lavinia's grandfather loved his mother and jealously cast his brother out of the family. Brant has sworn vengeance.

      A moment later, Lavinia appears inside her father's study. Christine enters indignantly, wondering why Lavinia has summoned her. Lavinia reveals that she followed her to New York and saw her kissing Brant. Christine defiantly tells Lavinia that she has long hated Ezra and that Lavinia was born of her disgust. She loves her brother Orin because he always seemed hers alone.

      Lavinia coldly explains that she intends to keep her mother's secret for Ezra's sake. Christine must only promise to never see Brant again. Laughingly Christine accuses her daughter of wanting Brant herself. Lavinia has always schemed to steal her place. Christine agrees to Lavinia's terms. Later she proposes to Brant that they poison Ezra and attribute his death to his heart trouble.