In act 3, John Proctor takes his household servant, Mary Warren, before Deputy Governor Danforth, the chief judge of the court in the Salem witch trials, to have Mary give testimony to Danforth that Proctor hopes will exonerate his wife, Elizabeth, and other members of the Salem community who have been accused of witchcraft by Abigail Williams.
When Mary first appears before Danforth, she’s frightened and reluctant to speak, and Proctor tells Danforth that Mary would tell him that “she never saw no spirits.” Danforth prevails on Mary to speak for herself.
DANFORTH: And you, Mary Warren, how came you to cry out people for sending their spirits against you?
MARY: It were pretense, sir.
DANFORTH: Ah? And the other girls? Susanna Wallcott, and—the others? They are also pretending?
MARY: Aye, sir.
At first, Danforth refuses to accept Mary’s written deposition because he’s suspicious of Proctor’s motives, and Danforth is encouraged in his suspicions by Reverend Parris, who remarks to Danforth, “He‘s come to overthrow this court, Your Honor!”
Proctor tells Danforth that Mary “swears now that she never saw Satan; nor any spirit, vague or clear, that Satan may have sent to hurt her. And she declares her friends are lying now.”
Danforth decides to accept Mary’s deposition but not before admonishing Mary for changing her testimony.
DANFORTH. I will tell you this—you are either lying now, or you were lying in the court, and in either case you have committed perjury and you will go to jail for it. You cannot lightly say you lied, Mary.
Danforth has two of the supposedly bewitched young girls, Susanna Walcott and Mercy Lewis, brought into the room, along with the primary accuser, Abigail Williams. Danforth questions Abigail, but she has an answer for every one of his questions.
As Danforth presses Abigail with more questions—and Proctor accuses Abigail of instigating a plot to murder his wife and other members of the community by accusing them of witchcraft—Abigail begins acting like she sees Mary in the form of a bird on the ceiling, threatening to attack her and the other girls, who also join in the “vision.” Mary succumbs to the pressure that Abigail puts on her, and she turns on Proctor, calling him “the Devil’s man!” Mary claims that Proctor came to her every day and every night to get her to sign what Reverend Parris prompts her to say is “the Devil’s book.”
Abigail successfully turns Danforth's attention from herself to Proctor, and by intimidating Mary with her "vision," she gets Mary to accuse Proctor of witchcraft, for which Danforth condemns him to death.