At the beginning of the play, Mary is depicted as a timid and easily influenced person who is susceptible to manipulation. She is initially hesitant to speak out about the accusations of witchcraft, but eventually gives in to pressure from her fellow accusers and begins to name names, including John Proctor, one of the play's main characters.
As the trials progress, Mary becomes increasingly uncomfortable with the situation and begins to question her own actions. She eventually decides to recant her testimony, which puts her in danger of being accused of witchcraft herself. Despite this risk, Mary is determined to do the right thing and decides to tell the truth, even if it means risking her own life.
In the final scenes of the play, Mary is put on trial for witchcraft. Despite the efforts of John Proctor and others to defend her, she is found guilty and sentenced to death. However, before her execution can be carried out, she manages to escape with the help of John Proctor and his wife Abigail.
Ultimately, Mary Warren survives the Salem witch trials and is able to leave Salem, escaping the threat of execution and the oppressive atmosphere of the town. She serves as a symbol of hope and redemption in the play, as she is able to overcome her fear and stand up for what is right, even in the face of great danger.