In Act III of "The Crucible," what is Mary Warren's lie in court?
When Mary realizes that Abigail and the other girls are going to persist with their accusations against her in court, she says to her employer, John Proctor, "You're the Devil's man!" Then, when questioned further by Deputy Governor Danforth, she lies again, saying,
He come at me by night and every day to sign, to sign, to— . . . My name, he want my name. "I'll murder you," he says, "if my wife hangs! We must go and overthrow the court," he says! . . . He wake me every night, his eyes were like coals and his fingers claw my neck, and I sign, I sign . . .
In other words, then, Mary accuses John of being in league with the Devil and of trying to lure her into an alliance with the Devil as well. She lies, saying that John threatened her, saying he would kill her if his wife, Elizabeth is convicted of witchcraft. She lies again, saying that John wanted her to come with him to overthrow the court, knowing that this is precisely what Parris and Danforth seem to want to believe of him. Mary lies more, claiming that John came to her in the middle of every night with beady, burning eyes, clawing and pawing at her, forcing her to sign her name in the Devil's book, as he has done. She tells precisely the lies that she knows will convince the judges of John's evil nature because she has heard these lies told about other people who have been convicted of witchcraft.
Mary Warren, in Act III, after she submits testimony to the court, telling the truth for the first time, she is unsuccessful. The court does not believe her, the judge warns her that if she has lied to the court at all, she will hang.
Mary Warren gets scared, terrified as a matter of fact, she turns and accuses John Proctor of being in league with the Devil and of trying to get her to join him. She lies.
She continues to lie, she claims that he has threatened her, she says. She lies and tells the court that he has threatened to kill her if she did not lie in court to get Elizabeth Proctor free.
Mary Warren dooms John Proctor. She lies about him to save herself. She is responsible for getting him arrested and ultimately executed.