The hopeful tone of Act II changes dramatically at the beginning of Act III as Romeo becomes embroiled in the brutal conflict between the families. The searing heat, flaring tempers, and sudden violence of this scene contrast sharply with the romantic, peaceful previous night. The play reaches a dramatic crescendo as Romeo and Juliet's private world clashes with the public feud with tragic consequences. Mercutio's death is the catalyst for the tragic turn the play takes from this point onward.
True to character, the hot-headed Mercutio starts a quarrel the instant Tybalt requests a word with him, by responding, "make it a word and a blow." Tybalt at first ignores Mercutio's insults because, ironically again, he's saving his blade for Romeo.
Romeo, by contrast, is as passionate about love as Tybalt and Mercutio are about hostility. Romeo appears, cheerful and contented with having wed Juliet only hours before, and unaware that he's even been challenged to a duel. Until Mercutio dies, Romeo remains emotionally distinct from the other characters in the scene. Romeo walks atop his euphoric cloud buoyed by blissful thoughts of marriage to Juliet, peace, unity, and harmony. In response to Tybalt's attempts to initiate a fight, Romeo tells Tybalt that he loves "thee better than thou canst devise." Ironically, Romeo's refusal to duel with Tybalt brings about the very acceleration of violence he sought to prevent.
In Romeo's mind, he has shed his identity as a Montague and has become one with Juliet, his wife. Romeo's separation echoes the balcony scene where he said "Call me but love…Henceforth I never will be Romeo." However, Tybalt seeks revenge against Romeo because a Montague appeared at a Capulet ball. While Romeo no longer labels himself Montague, Tybalt still sees Romeo as standing on the wrong side of a clear line that divides the families.
