In the pastry shop, the cadets call for Cyrano to tell the story of his violent clash with the soldiers the previous night. Cyrano says he’ll tell the story in due time.
Cyrano clearly isn’t himself: it’s not like him to turn down the opportunity to tell a story, particularly one that highlights his own bravery and prowess.
A cadet walks by Christian’s table and calls Christian a weak, inexperienced boy. He also warns Christian never to say the word “nose” in front of Cyrano. Another cadet chimes in, explaining that in the past Cyrano has killed men because they brought up his enormous nose.
The cadets are teasing Christian, but it’s also impossible to tell how much: we’ve seen Cyrano fight (non-lethal) duels because of an insult about his nose, but to actually kill someone over such an insult seems excessive.
Christian walks to his Captain, Carbon de Castel-Jaloux. He asks Carbon what a Northerner (which Christian is) can do to prove himself to a group of Southern Frenchmen (the cadets in the shop). Carbon tells Christian that he must demonstrate his bravery in some way.
At this point in French history, France wasn’t a strong, consolidated nation-state—it was a loose confederation of provinces, each with its own culture. Christian, a Northerner among Gascons (Southern Frenchmen), naturally wants to prove himself so that he isn’t treated like such an outsider.
Cyrano begins to tell the cadets the story of his conflict with the soldiers the previous night. The night was very dark, he begins. Christian interrupts Cyrano, saying the night was so dark that Cyrano must have been able to see his nose and nothing else. The cadets are dumbfounded by Christian’s insult. Cyrano, furious, asks a cadet for Christian’s name. Remembering his promise to Roxane, however, Cyrano forces himself to be calm, and goes on. He explains how he ventured outside of the city, where he found “a hundred brawling sots.” Christian interjects with puns and jokes about Cyrano’s nose, and each time he does so Cyrano moves on with his story, barely concealing his fury. Finally, in the midst of the story, Christian makes a nose joke, and Cyrano bellows, “Out! All of you!” The cadets, Carbon, and Ragueneau, sure that Cyrano is going to murder Christian, flee the room instantly.
In this hilarious scene, Christian tries to show his bravery by insulting Cyrano, and Cyrano—much to everyone’s amazement—doesn’t do anything about it, since he’s sworn to Roxane that he’ll look out for Christian’s safety. Rostand cleverly exploits the dramatic irony of this situation: we know that Christian has nothing to fear (whatever he says, Cyrano won’t attack him), but neither Christian nor the other cadets are aware of this. At the same time we get to witness Cyrano’s inner struggle, as his pride and reputation does battle with his loyalty and honor—and loyalty wins out.