Mary Warren from "The Crucible"

Mary Warren from the Crucible was secretly planning to kill John and Elizabeth Proctor, controlling Abigail, and setting all three of them up to be killed. When she reluctantly agrees to go with him to court, she is planning to betray him and set him up for disaster. She even goes as far to create a deposition in which she stating that Abigail is a liar, all to make it appear that John Proctor is evil when she eventually betrays him. In the play, she comes with him to the court and pretends to agree with him until her puppet, Abigail, pretends to be bewitched, which could only have happened if it was planned between the two of them. When she abandons John Proctor's side and joins Abigail, she make him look like he forced her to agree with him, which would definitely be considered evil, and was attempting to lie about Abigail to get her killed and bring down the court. The timing of Mary's abandonment of John Proctor is too convenient to not have been a dastardly plan from the beginning. Combined with the fact that she set up Elizabeth Proctor too, it is too convenient to be a coincidence. When she gives the poppet to Elizabeth, she is setting up Elizabeth to be accused of being a witch. She tells Abigail, her puppet, to accuse Elizabeth since she set up the poppet to have a needle in it which would be clear proof that Elizabeth is a witch. When she knits the poppet and gives it to Elizabeth, the only way Abigail could know to stab herself and accuse Elizabeth would be too have Mary Warren controlling her and telling her what to do the entire time. When Abigail runs off at the end of the play, it is not because she fears what the people of the village will do, she fears Mary Warren's revenge. So although Mary seems like a meek and quiet child, she is a secret psychopath plotting and controlling everything from the shadows.