How does the duel between Mercutio and Tybalt in Act III, Scene 1 of Romeo and Juliet develop the plot?
This duel is crucial to the plot because it leads to Romeo's banishment. Romeo has just married Juliet in secret and does not want to fight Tybalt, Juliet's, and by extension his, kinsman. But his cousin Mercutio does, and when Romeo steps in to try to stop the duel, Tybalt runs Mercutio through, leaving him fatally wounded. Incensed, and with his honor bruised, Romeo fights Tybalt and kills him. For this offense, Romeo is banished, and this, of course creates a serious problem, one compounded by the Capulets' decision that Juliet will marry Paris. It is in response to this problem that Friar Lawrence develops the plan that ultimately leads to the tragic final scene in the Capulets' family crypt.