In Act Three, Mary Warren testifies that Abigail and the girls are lying and John Proctor confesses to committing adultery with Abigail in order to damage her revered reputation. After John Proctor confesses to lechery, Abigail begins to act like she sees Mary Warren's spirit in the rafters and the other girls join along. As Abigail pretends to have a conversation with Mary's spirit in the form of an invisible bird, Mary Warren protests and claims that the girls are lying. Mary Warren then demands that Abigail and her followers stop pretending to see her spirit but they continue to act like they are threatened and begin to mimic her. Each time Mary Warren speaks, Abigail and the girls repeat her words, which builds the suspense and begins to confuse Mary. Danforth then starts to question Mary, who feels the pressure of the girls and Salem's authority figures at the same time. Mary Warren becomes confused and overwhelmed with fear during the scene until she finally joins Abigail and the girls. Mary Warren then accuses John Proctor of colluding with the devil, which illustrates the extent of her confusion and fear, as well as the power of Abigail's influence.

In Act III, when Mary Warren is brought by Proctor to testify against Abigail and the other girls, they are quick to act to attack Mary and also to defend their own position. When pressurised, Abigail feigns a visitation of another spirit that she claims is Mary Warren, and which she and all the girls react to. Once Abigail has started to freeze, the others quickly follow suit, accusing Mary of being the cause. Note what Mercy Lewis says to her:

Mary, do you send this shadow on me?

Mary as a result crumbles and tries to flee the courtroom. She is clearly terrified of the influence that Abigail has over the girls and how they have turned against her. It is this that causes her to rejoin Abigail and the girls and go against what she told Proctor before. Mary is confused by the way the girls deliberately turn on her and break her.