So what?

This passage (III. i. 34-134) adds much heated conflict to the play.  First of all, two deaths occur—one of Mercutio, and one of Tybalt.  While Mercutio dies, defeated through underhand trickery, he screams at both of the houses, blaming their conflict for his death.  Mercutio, seeing Tybalt in the street, exchanges some verbal blows with him, and then they fight.  Romeo makes an attempt to intervene, and while Mercutio is stunned, Tybalt stabs him under Romeo’s arm and flees.  Mercutio delivers his ‘Zounds, I’m dying’ speech, and is presently dragged offstage by Benvolio to see a doctor.  Romeo then follows Mercutio’s speech with a ‘Curses, this is all my fault’ speech, and ends it by stating how Juliet’s beauty has befouled his mind.  Benvolio then returns and makes an official statement; Mercutio is dead.  Then Tybalt returns, and Romeo, in his suppressed rage, challenges and kills him.  So now, the Prince, who has directly pronounced the punishment for fighting in Verona as death, will be chasing Romeo as well.  And there is no way he can lie his way out, because there were witnesses.  So now, with one of his best friends and his worst enemy dead, Romeo is plunged deeper into the sky of chaos, his hands red with the slanderous blood of Tybalt.