Answer:
Mercutio
Step-by-step explanation:
In act III, scene I, a fight takes place where Tybalt and Mercutio draw their swords in battle. Mercutio is seriously injured and addresses Romeo to inquire why the enmity between the two houses, the Capulets and the Montagues', affects the city of Verona and has caused his major wound. "A plague a' both your houses!", says Mercutio to Romeo out of anger. This event is crucial to the development of the plot for it is in the death of his beloved friend where Romeo finds his justification for slaying Tybalt, deed which causes Romeo to escape.