Act III, Scene I in Shakespeare's play, Romeo and Juliet, is significant because it changes the direction and mood of the play. Shakespeare introduces tragedy with the deaths of Mercutio and Tybalt, steering the play in a direction other than love. As in life, actions have consequences, and this scene especially allows Romeo to see this fact.
The first real tragedy of the play is Mercutio's death. As he dies, he foreshadows the ensuing flavor of death awaiting both families when he says, “A plague o’ both your houses” (3.1.91), according a student analysis on the Towson University website. The next tragedy in this scene unfolds in minutes as Romeo acts impulsively and kills Tybalt. Suddenly, things are much worse than before. If the death of two characters were not enough, Lady Capulet ensures Romeo’s fate of exile when she states, “Affection makes him false; He speaks not true” (3.1.177). The Prince does not act for revenge, but instead, acts to keep the peace, exiling Romeo. Hence, the play takes a turn for the worse. This scene shifts the mood of the play from love to tragedy, while focusing on the consequences of actions. Romeo acts hastily and cannot take back what he has done. The scene also emphasizes the importance of free will in a world full of obstacles and challenges.