The play's protagonist, Beauford, is about to marry the heroine, Gratiana, when Beauford's cousin Marwood claims that he has been Gratiana's lover. The two men duel over the matter, and Marwood loses — but as he dies he maintains the truth of his accusation. At the house where the ceremony is about to occur, Beauford takes Gratiana aside and tells her of the matter; though Gratiana denies Marwood's allegations, Beauford does not believe her. As Beauford waits to be arrested for Marwood's killing, Gratiana is offered concealment by Captain Landby, who also delivers a letter from Gratiana to her estranged fiance. The letter tells Beauford that by the time he reads it, she will have drowned herself. Gratiana's page Millicent advises her to confront her waiting woman Cardona about the whole matter.