Final answer:
Mary Warren lies in Act 3 of 'The Crucible' by accusing John Proctor of being 'the Devil's man,' a false allegation made to protect herself under the pressure of the court and the intimidation from Abigail Williams and the other girls.
Step-by-step explanation:
The student is asking about a specific event in Act 3 of The Crucible by Arthur Miller involving a character named Mary Warren. Mary Warren, who is a servant and a member of the Proctor household, lies about her involvement with the other girls in the Salem witch trials and about being affected by witchcraft. In Act 3, when Mary is brought to court by John Proctor to confess that the girls are only pretending to be affected by witchcraft, she is intimidated by Abigail Williams and the other girls, who pretend Mary is attacking them with her spirit. Under this immense pressure and the threat of being accused of witchcraft herself, Mary Warren retracts her confession and accuses John Proctor of being "the Devil's man," thereby lying to protect herself from possible retribution.