What is the tone and atmosphere during Act III, Scene 1 of Romeo and Juliet?

The tone of a piece of literature is the attitude the author takes toward the audience, a subject or a character. The mood or atmosphere is the feeling created in the reader by the scene or passage. Act III, Scene 1 of Shakespeare's Romeo and Juliet is considered the turning point of the play. It begins the descent toward death and suicide of five of the main characters.

The tone throughout this scene is displayed in the passion of the principal characters. Benvolio is anxious and concerned. Mercutio, on the other hand, displays his typical arrogance and biting humor. Later, he will become bitter and cursing in his tone as he dies after the fight with Tybalt. Tybalt is angry and belligerent. Romeo, who at first is cheerful (he has just married Juliet), later becomes intense and driven.

The mood or atmosphere can be found in the words of Benvolio and Mercutio. The very first lines spoken by Benvolio suggest suspense and they put the audience on the edge of their seats. His warning to Mercutio to get off the street incites a mood of anticipation:

I pray thee, good Mercutio, let’s retire.
The day is hot, the Capels are abroad,
And if we meet we shall not ’scape a brawl,
For now, these hot days, is the mad blood stirring.

This anticipation is suspended for a time with Mercutio's  absurd rant about Benvolio being a fighter. The mood soon turns suspenseful again as Tybalt enters the scene and he and Mercutio banter back and forth. Finally, the mood abruptly turns violent as Mercutio, enraged at Romeo's seeming cowardice, challenges Tybalt:

O calm, dishonorable, vile submission!
Alla stoccato carries it away. [He draws.]
Tybalt, you ratcatcher, will you walk?

This violent mood continues as Romeo realizes his acquiescence toward Tybalt has caused Mercutio's death. When Tybalt returns, the fighting continues and Tybalt is killed. The last part of the scene takes on a mood of tension as Lady Capulet lies about the fighting and calls for the death of Romeo. This tension, verging on more suspense, is only increased as the Prince sentences Romeo to exile. The audience is now anxious to see how the tragedy will play out.