The document summarizes the structure of Arthur Miller's play The Crucible by outlining the key events and characters introduced in each of the four acts. Act I establishes the fear of witchcraft spreading in Salem and introduces many main characters. Act II shows the tense relationship between John and Elizabeth Proctor and their impending arrest. Act III takes place in the courtroom and presents a struggle between superstition and reason. Act IV allows John Proctor to become a heroic character who chooses death over denying his good name.