Caesar, having entered Rome in triumph, calls to his wife, Calphurnia, and orders her to stand where Mark Antony, about to run in the traditional footrace of the Lupercal, can touch her as he passes. Caesar shares the belief that if a childless woman is touched by one of the holy runners, she will lose her sterility.
A soothsayer calls from the crowd warning Caesar to "beware the ides of March," but Caesar pays no attention and departs with his attendants, leaving Brutus and Cassius behind.
Cassius begins to probe Brutus about his feelings toward Caesar and the prospect of Caesar's becoming a dictator in Rome. Brutus has clearly been disturbed about this issue for some time. Cassius reminds Brutus that Caesar is merely a mortal like them, with ordinary human weaknesses, and he says that he would rather die than see such a man become his master. He reminds Brutus of Brutus' noble ancestry and of the expectations of his fellow Romans that he will serve his country as his ancestors did. Brutus is obviously moved, but he is unsure of what to do.
Several times during their conversation, Cassius and Brutus hear shouts and the sounds of trumpets. Caesar re-enters with his attendants and, in passing, he remarks to Mark Antony that he feels suspicious of Cassius, who "has a lean and hungry look; / He thinks too much. Such men are dangerous."
As Caesar exits, Brutus and Cassius stop Casca and converse with him. He tells them that Mark Antony offered the crown to Caesar three times, but that Caesar rejected it each time and then fell down in an epileptic seizure. The three men agree to think further about the matter, and when Casca and Brutus have gone, Cassius in a brief soliloquy indicates his plans to secure Brutus firmly for the conspiracy that he is planning against Caesar.
