In act three of The Crucible, John Proctor and his friends present many pieces of very sound, logical evidence to try to prove both the innocence of their wives and the deception of the girls who are behind all of the accusations. Unfortunately, every single attempt fails. The first, a petition of 99 people attesting to the innocence of the women, is dismissed and those 99 people themselves are arrested. Then, when Giles Corey brings forth a testimony of someone who heard Putnam prompt his daughter to cry out witchcraft on Jacobs in order to get his land, Corey is arrested for not releasing the name of the witness.
Their last hope rests in Mary Warren's testimony that the girls are pretending. However, that fails when Mary can't faint all alone, and, then, Abby starts pretending that Marry Warren is bewitching her in the courtroom. Abby claims to be icy cold, and that it is Mary's spirit doing it to her. The judges automatically believe her. After that, when John's attempt to prove Abby dishonest because of his affair fails, Abby goes at it again. She leads all of the girls in claiming that Mary's spirit has come into the courtroom in the form of a yellow bird that wants to claw her eyes out. Again, the judges believer her completely. The judges are so convinced, in fact, that Ma turns on John and calls him a "Devil's man" so that the girls will stop making her look like the witch.
The hard thing to believe, for us, is that the courts believed these girls; however, because of their society's belief in the devil and wit chcraft, and probably through some great acting on the girls' parts, they did. I hope that helped; good luck!
In Act III, when Mary Warren brings her testimony that the girls have been lying all along, Abigail first begins by insisting on her own truthfulness and claiming that Mary is the one who is lying. Abigail alters her tone, adopting "a slight note of indignation" when she is questioned again as a result of Mary's testimony. Further, she lies again in regard to Elizabeth Proctor, saying that the woman has "always kept poppets." When Danforth insists that Abby "search [her] heart" and answer him truthfully, she becomes extremely self-righteous, talking of the sacrifices she's made for the town and the irony of "mistrust[ing]" her when she's "done [her] duty pointing out the Devil's people [...]." When she sees him weakening at this, she makes an "open threat," telling Danforth that he should beware: "Think you to be so mighty that the power of Hell may not turn your wits?" It is now that she blames Mary for sending "a cold wind," and the other girls back her up. Therefore, Abigail tells more lies, adopts a haughty tone when questioned again as though such questioning is an affront to her, blatantly threatens the deputy governor, and then accuses Mary of witchcraft in order to make her appear to be the guilty one (an accusation in which the other girls support her).
The girls being led by Abigail pretend to be possessed or haunted by evil spirits sent to them by those they accused.
Parris: Aye, faint. Prove to us how you pretended in the court so many times.
Mary Warren, looking to Proctor: I - cannot faint now, sir.
The girls also used information about certain events to frame some of the people in Salem. For instance, in the case of Elizabeth, the officials were sent to Proctor’s house to retrieve the poppet that had a needle in the stomach, this was the same poppet Abigail saw Mary making while in court. Abigail claimed stomach pains and directed Danforth’s team to the alleged instrument of witchcraft and it was on this basis that Mrs. Proctor was arrested and charged with witchcraft.
John Proctor asked Mary to testify in court given the poppet was her innocent creation with not association to witchcraft. Mary agreed and testified, however while giving her testimony, the girls accused Mary of working for the devil and sending an evil spirit to torment them. They acted weirdly and mimicked every word she said. Mary was forced to rescind her initial testimony and instead joined the girls by falsely accusing John of working for the devil and forcing her to interfere with the case.
Danforth, himself engaged and entered by Abigail: Mary Warren, do you witch her? I say to you, do you send your spirit out?
Mary Warren, pointing at Proctor: You're the Devil’s man!