In Act III, when John Proctor brings his servant, Mary Warren, to the court, she has promised to tell the truth.  As a result, she confesses that the girls' histrionics in the courtroom, including her own, were "pretense."  In other words, they were lies.  Reverend Parris says that when he touched her then, her skin was cold, and Proctor assures the court that she'd only been "pretend[ing] to faint."  Judge Hathorne then asks if she can pretend to faint now.  Reverend Parris commands her to "Faint!" and prove that she had done it before.  The stage direction tells us that "She looks about as though searching for the passion to faint," but she seems at a total loss in this quiet moment, standing there with everyone staring at her.  She tries to explain that she used to faint because "[she] thought [she] saw spirits" and all the other girls were screaming and crying.  When Danforth then turns to Abigail for an explanation of her past behavior, she threatens him and begins to accuse Mary Warren of sending out her spirit to hurt the girls.  Eventually, Mary Warren turns on Proctor and he is arrested, charged by her with witchcraft.

Mary, meanwhile, is questioned by the judge and asserts several times that she has lied in court. Susanna Walcott, Mercy Lewis, Betty Parris, and Abigail are led into the room and told of Mary’s confession. Abigail, asked if there is any truth to it, flatly denies it. As Abigail calmly refutes all of Mary’s assertions, her character is called into question by Proctor, who tells the others that she has led the girls to dance naked in the woods. Parris is forced to admit that he discovered them dancing. Mary is then asked to fake fainting, as she says she did in the courtroom. She is unable to comply.