Act 3 opens with Mercutio and Benvolio walking as usual around the town. Benvolio's keen instinct is telling him that a brawl could erupt in the street at any moment, and he warns Mercutio that they should go home at once. Mercutio is not as peace loving as his dear friend and chastises Benvolio for even suggesting that they cower inside. To aggravate Benvolio, Mercutio cites nonsensical examples of fights Benvolio has participated in -- one with a man cracking nuts, another with a man who tied his new shoes with 'old riband'. Benvolio sees the Capulets coming and knows a confrontation is inevitable. Tybalt demands to see Romeo so that he can slay him with his ever-ready rapier. Mercutio confronts Tybalt, but, because Mercutio is not a Capulet, Tybalt brushes him aside and moves straight toward Romeo who has just come upon the scene. Romeo, now related to Tybalt, refuses to fight. He cannot reveal why he does not defend his honour, but suggests that they should stop the bitter feud and embrace each other once and for all:
I do protest, I never injured thee,
But love thee better than thou canst devise
Till thou shalt know the true reason of my love;
And so, good Capulet,-- which name I tender
As dearly as mine own,-- be satisfied (3.1.70-4).
Mercutio cannot stand by and watch Romeo stand down like a common coward. He draws his sword and challenges Tybalt. Romeo tries to stop the fight but to no avail -- Tybalt fatally wounds Mercutio. He dies cursing both families, "a plague on both your houses/They have made worms meat of me" (3.1.91-2), despite the fact that his own intemperance has caused his death. Romeo is crushed by the knowledge that Mercutio has lost his life for him, and he draws his sword, attacking Tybalt with ferocity. Tybalt is no match for the skilled and enraged Romeo, and he falls dead to the ground. Romeo stands over Tybalt and all the consequences of his actions flood his mind. By the Prince's decree, Romeo will be executed for disobeying the peace, thus leaving Juliet a widow. And he has betrayed his new bride by killing her beloved cousin. The Prince, the Capulets, and Montague happen upon the tragic scene and Benvolio tries his best to explain why Romeo was forced to kill Tybalt. Because Romeo has slain the instigator of the violence and the murderer of Mercutio, the Prince decides that Romeo should not be executed but banished from Verona instead. If Romeo ever returns, Prince Escalus cautions, he will certainly be killed.