At the Forum (a.k.a. the marketplace) in Rome, a bunch of plebeians have gathered to hear Coriolanus speak.
Some of them feel like they're being put in a tough spot. They don't really like Coriolanus, but since he's a war hero, they feel obligated to vote for him if he shows up, gives them some lip service, and shows them his wounds.
Coriolanus finally shows up. And yes, he's wearing the special toga (a.k.a. the "gown of humility").
Like a good politician, Coriolanus swallows his pride (sort of) and tells the plebeians what they want to hear (sort of).
Even though he goes through all the motions, he's still super arrogant and has a hard time being nice.
Nobody calls him on it, and eventually, the plebeians agree to give him their votes and he leaves.
The tribunes (Sicinius and Brutus) show up and want to hear all the dirt.
Some of plebeians say they think Coriolanus was kind of a jerk, and someone even chimes in that, hey, Coriolanus never actually showed off his battle wounds.
So why did they vote for him, anyway?
Nobody can give them a good answer.
Sicinius and Brutus get the plebeians all riled up and tell them that they should take back their votes so Coriolanus can't be named consul of Rome. Otherwise, they say, the guy will take away everyone's "liberties."
Now Sicinius and Brutus convince the plebeians to storm the Capitol and stage a mutiny.
Then they're all "Oh, but don't tell anyone we put you up to this. If anyone asks, we're the ones who told you to vote for Coriolanus. Okay?"
The plebeians run off to get their riot on.
Meanwhile, Sicinius and Brutus hang back and brag about how they've stirred up a ton of trouble for Coriolanus.