Act 1, Scene 1
The story opens on a street in Rome, where two tribunes, Flavius and Marullus, disperse a crowd that is celebrating the return of the greatest ruler of the day, Julius Caesar. The tribunes, fearful of Caesar's ever-increasing power, berate the assembled commoners for their shortsightedness and fickle loyalties. Marullus reminds the cobblers and carpenters that Caesar has conquered another Roman, the noble Pompey:
O you hard hearts, you cruel men of Rome,
Knew you not Pompey? Many a time and oft
Have you climb'd up to walls and battlements,
To towers and windows, yea, to chimney-tops,
Your infants in your arms, and there have sat
The livelong day, with patient expectation,
To see great Pompey pass the streets of Rome:
And when you saw his chariot but appear,
Have you not made an universal shout,
That Tiber trembled underneath her banks,
To hear the replication of your sounds
Made in her concave shores?
And do you now put on your best attire?
And do you now cull out a holiday?
And do you now strew flowers in his way
That comes in triumph over Pompey's blood? Be gone! (40-56)
The crowd scatters and Flavius and Marullus remove the decorations that cover the public statues.
Act 1, Scene 2
Caesar passes through a public square to celebrate the Roman festival of Lupercalia. With Caesar is his wife Calpurnia, Mark Antony, senator Cicero, republican sympathizers Brutus, Cassius, Casca, Decius, Flavius, Marullus, and Brutus' wife Portia. Caesar asks Antony to touch Calpurnia in a fertility rite,
for our elders say,
The barren, touched in this holy chase,
Shake off their sterile curse. (7-9)
As the music and merriment begins, Caesar hears someone shout his name. Hushing the crowd, he asks the voice to speak again. A soothsayer comes into view and warns Caesar to "Beware the ides of March", but Caesar ignores his premonition: "He is a dreamer; let us leave him; pass" (24). Caesar and the adoring multitudes move on to the festival, but Brutus and Cassius stay behind.
They remain to discuss Caesar's thirst for power and his desire to turn the republic into a dictatorship. Cassius is already prepared to assassinate Caesar to save Rome from tyranny, and he attempts to convince Brutus that the murder would be justified:
Brutus and Caesar: what should be in that 'Caesar'?
Why should that name be sounded more than yours?
Write them together, yours is as fair a name;
Sound them, it doth become the mouth as well;
Weigh them, it is as heavy; conjure with 'em,
Brutus will start a spirit as soon as Caesar.
Now, in the names of all the gods at once,
Upon what meat doth this our Caesar feed,
That he is grown so great? Age, thou art shamed!
Rome, thou hast lost the breed of noble bloods!
When went there by an age, since the great flood,
But it was famed with more than with one man? (141-50)
Although Brutus reveals he has contemplated conspiring against Caesar, he will not immediately involve himself in Cassius's plot. Rather, Brutus agrees to ponder all that Cassius has said and meet with him again to "answer such high things" (169). Caesar and his entourage return, and Caesar confides to Antony that he mistrusts Cassius.
Let me have men about me that are fat;
Sleek-headed men and such as sleep o' nights:
Yond Cassius has a lean and hungry look;
He thinks too much: such men are dangerous.
Antony assures Caesar that Cassius is a noble and trustworthy Roman incapable of treachery, but Caesar remains unconvinced.
Would he were fatter! But I fear him not:
Yet if my name were liable to fear,
I do not know the man I should avoid
So soon as that spare Cassius. (197-200)
Caesar and his train leave but Casca remains behind after Brutus pulls him by the cloak. Casca tells Brutus and Cassius about the festival, and how Antony offered Caesar a crown three times and three times he refused it. But, in Casca's opinion, Caesar only refused the crown to please the crowd. In fact, the people so loved the gesture that they "uttered up such a deal of stinking breath ... that it almost choked Caesar; for he swounded and fell down at it" (246-9). Casca finishes recounting Caesar's actions at the festival and, after declining a dinner invitation from Cassius, bids the men farewell. Cassius feels Casca's report is more evidence to suspect Caesar has plans to become king. Brutus asks to see Cassius again the next day and leaves Cassius alone to ponder the chances that Brutus will not agree to join the plot. After all, Cassius knows his arguments have not been thoroughly convincing, and it is apparent that Caesar loves Brutus and would reward his loyalty with great wealth and power. Thus Cassius concludes that he must help his own cause with a little trickery. He will fabricate a petition, pretending it is from the angry citizens demanding Caesar's deposition, and he will throw it in Brutus' window.
Act 1, Scene 3
Scene three opens amidst a great storm. Thunder shakes the foundations of Rome and aberrant lighting slices through the night sky. Casca appears with his sword drawn and sees Cicero coming towards him. Casca speaks of the omens he has witnessed this stormy night, including wild beasts roaming the Capitol and men on fire. Cicero makes little of the portents and hurries home, anxious to be out of the wind and rain. Casca next encounters Cassius, who uses the storm as a means to recruit Casca for his plot:
Now could I, Casca, name to thee a man
Most like this dreadful night,
That thunders, lightens, opens graves, and roars
As doth the lion in the Capitol,
A man no mightier than thyself or me
In personal action, yet prodigious grown
And fearful, as these strange eruptions are.
Another conspirator named Cinna arrives and Cassius tells him that Casca is their newest confidant. Then Cassius instructs Cinna to throw the petition into Brutus' window and meet him and the other conspirators at Pompey's theatre.
Act 2, Scene 1
Brutus, unable to sleep, walks through his orchard awaiting dawn. He replays his conversations with Cassius in his mind, divided between his love for Caesar the man and his fear that Caesar’s unlimited power will destroy the Republic. Brutus orders his servant Lucius to light a taper in his office and, when Lucius returns he brings the false petition that Cinna has planted. Brutus reads the letter and, just as Cassius had hoped, it arouses Brutus' passions. The conspirators arrive at Brutus' house and Lucius leads them to the orchard. Not knowing if Brutus has decided to join them, the group exchanges pleasantries until Cassius takes Brutus aside. When the two rejoin the group, Brutus asks for the hands of the conspirators as he agrees to lead them in the assassination plot. As they begin to plan the murder, Brutus insists that they do not harm Antony:
Our course will seem too bloody, Caius Cassius,
To cut the head off and then hack the limbs,
Like wrath in death and envy afterwards;
For Antony is but a limb of Caesar:
Let us be sacrificers, but not butchers, Caius. (162-6)
Dawn is breaking, and the conspirators must depart. Before they leave Decius offers to ensure that Caesar will be in the Capitol the next day, the fifteenth of March. They will commit the murder by the eighth hour. Just as the men leave, Brutus' wife Portia comes to find her husband. She is perplexed by Brutus' strange behavior of late and begs him "Make me acquainted with your grief" (256). Brutus hears a knock at the door and promises Portia he will reveal the cause of his grief later. He delicately orders her to hurry back to bed. Lucius enters with Ligarius, another conspirator. Ligarius tells Brutus that he will do anything Brutus asks, and they leave together to commit the act that "will make sick men whole" (327).
Act 2, Scene 2
Like Portia, Calpurnia has trouble sleeping. She has heard of the beasts roaming the Capitol and other strange occurrences, and begs him not to go to the Capitol. After much reluctance Caesar agrees to stay home, but just as he does so, Decius arrives to escort Caesar to the senate-house. When Caesar informs Decius that he will not go because of Calpurnia's request, Decius chides him for yielding to his wife's whims. Decius adds that the senate has concluded that they will today give Caesar a crown, and Caesar gives into vanity, agreeing to accompany Decius to the Capitol.
Act 2, Scene 3
Meanwhile, on a street near the Capitol, a scholar named Artemidorus has discovered the plot to murder Caesar and has written the names of the conspirators on a paper which he plans to hand to Caesar as he passes by.
Act 2, Scene 4
Portia is standing on the street outside her house, frantically worried about Brutus. She orders Lucius to the senate-house to report on Brutus. Portia sees the soothsayer. He tells her that he has come to once again warn Caesar. He leaves to take his position along the procession route and Portia, weak with worry and fear, goes back inside.