⇛ In another public place in Rome, Caesar, accompanied by his followers, encounters a soothsayer, who tells him to beware the ides of March (March 15). Caesar dismisses him as a dreamer. Caesar and his entourage exit, leaving Cassius and Brutus to engage in conversation.

⇛ Cassius mentions that recently Brutus has not seemed so friendly towards him as he usually is. Brutus replies that it is nothing personal; he is troubled by some private business and this is affecting his behavior towards others. Cassius hints that he knows Brutus better than Brutus himself does.

⇛ He suggests that others in Rome who are suffering under Caesar's oppression have wished that Brutus would open his eyes to their plight and (Cassius implies) do something about it. He promises to tell Brutus something about himself that he is as yet unaware of.

⇛ As shouts are heard from the crowd offstage, Brutus says he fears that the people will choose Caesar for their king. Even though he loves Caesar, Brutus does not want him to be crowned king.

⇛ Cassius then gives a long speech in which he explains that Caesar is not fit to hold the great office that he does. He expresses his frustration at the inferior position he occupies in relation to Caesar, even though he was born just as free as the man who now rules.

⇛ Cassius relates an incident that showed he was a better swimmer than Caesar. He also observed Caesar when the latter had a fever, and he was not impressed. Caesar trembled and groaned, his eyes looked dull and his voice sounded feeble, like that of a sick girl. And yet this Caesar, who is physically weak, rules over Rome.

⇛ More shouts are heard from the crowd outside, which Brutus takes to be a sign that new honours are being heaped on Caesar. Cassius continues his complaint against Caesar and bemoans the fact that so much power is concentrated in one man. He castigates Romans for allowing it.

⇛ Brutus says he will consider Cassius's words, but he does not want to commit himself yet. Caesar and his entourage return. Caesar tells Mark Antony that Cassius is a dangerous man, although he hastens to add that he is not afraid of him, since he fears no one. But men like Cassius, Caesar observes, are never at rest while someone else holds power over them.

⇛ After Caesar exits, Casca explains to Cassius and Brutus that Antony just offered Caesar a crown three times. Each time Caesar rejected it, but each time he did so with greater reluctance. The crowd cheered when he rejected it for the third time, at which Caesar had an epileptic fit and fell down foaming at the mouth. Just before he collapsed, he theatrically opened his doublet, offering the crowd his throat to cut.

⇛ Casca also mentions that Flavius and Marullus have been executed for removing crowns from Caesar's statues. Their acts were considered treasonous. After all have left, Cassius is left alone. He reflects that although Brutus is a noble man, it is possible to be lure him away from his natural inclinations and persuade him to join the conspiracy to kill Caesar.

⇛ Cassius plans to write some letters, in different handwriting, and toss them through Brutus's window that night, as if they came from several different Roman citizens. The letters will confirm how high Brutus is held in public esteem and hint at Caesar's ambition.