Scene 1

At Antony’s house, Antony, Octavius, and the wealthy banker Lepidus—having formed the political body the Second Triumvirate—“prick,” or select, the names of anti-Caesar factions who must die. Octavius notes that Lepidus’s brother is on the list. Lepidus agrees to his brother’s inclusion on the condition that Antony show no mercy to Plubius, his sister’s son. “Look, with a spot I damn him,” says Antony, consenting to the exchange, and sends Lepidus to Caesar’s house to locate his will. Antony wants to divert some of the capital in Caesar’s will to their cause. After Lepidus exits, Antony wonders aloud if the “slight, unmeritable” man is fit to rule the new order he and Octavius are building. When Octavius defends Lepidus as a brave soldier, Antony retorts that so is his horse, and like a horse, Lepidus must be trained “to wind, to stop, to run directly on.” Antony directs Octavius’s attention from Lepidus toward “great things,” such as the fact that Brutus and Cassius are marshaling their forces outside Rome, and so must he and Octavius. Octavius agrees that the triumvirate are tied like prey “at the stake,” surrounded by baying, bloodthirsty enemies, and must get all the help they can.

Scene 2

At a camp near Sardinia, Brutus, his commander Lucillius, and Lucius receive Titinius and Pindarus, commanders in Cassius’s army. When Pindarus requests a meeting between Cassius and Brutus, Brutus asks Lucillius, who visited Cassius earlier, about the welcome Cassius offered him. Lucilius tells Brutus that though Cassius was polite and respectful, he was not as friendly as he used to be. Brutus notes that this signifies that Cassius has cooled toward him, as “When love begins to sicken and decay, / It useth an enforcèd ceremony.” Brutus, however, consents to meet Cassius. Cassius, who is also camped at Sardinia, enters the scene, complaining to Brutus that he has done Cassius wrong. Mindful of the presence of their soldiers and commanders, Brutus asks Cassius to speak to him privately.

Scene 3

In Brutus’s tent, Cassius drops his formal front and accuses Brutus of humiliating him by punishing Lucius Pella, Cassius’s friend, on the charge of taking bribes, despite Cassius’s written entreaties to spare Pella. Brutus, however, scolds Cassius for having “wronged [himself] to write in such a case,” leading Cassius to assail Brutus for his rigidity in such turbulent times. Brutus retorts that Cassius has developed an “itching palm,” insinuating that Cassius has developed a taste for bribes, a charge which leaves Cassius incensed. Brutus reminds Cassius of the Ides of March, when Caesar bled for justice’s sake. Given the enormity of their actions to rebuild Rome, the conspirators should display impeccable morals. Cassius warns Brutus not to “bait” him, and the two enter a bitter argument. One of the charges Brutus levies against Cassius is miserliness, citing the fact that Cassius refused to lend Brutus gold to pay off his soldiers. Cassius claims that he never refused Brutus and that his message was badly communicated. He says Brutus has “rived,” or broken, his heart by exaggerating his friend’s faults. After a dramatic exchange in which Cassius tells Brutus to kill him so that he will be spared Brutus’s judgment and dislike, Cassius and Brutus shake hands and reconcile.

Brutus asks Lucillus and Titinius to have the army camp at their location for the night. Cassius asks them to bring back Messala afterward. Over wine, Cassius questions the usually stoic Brutus about his rare display of rage earlier in the day. Brutus responds that his anger arose from his grief over Portia's death. Shocked at Brutus’s “insupportable and touching loss,” Cassius asks how Portia died. Brutus tells him that, worrying about Brutus and fearing that Antony and Octavius had grown too powerful, Portia gave into despair and committed suicide by “swallowing fire.” Overcome with melancholy, Brutus says he simply wants to drown his sorrows in wine.

Cassius and Brutus are joined by Messala. Already mindful that Antony and Octavius are moving arms toward Philippi, Brutus asks Messala for new intelligence. Messala reveals that the Triumvirate has accused a hundred senators—rather than seventy, as Brutus had previously believed—with treason, including Cicero.

Cassius opposes Brutus’s decision to march toward Antony and Octavius, suggesting they should be defensive and wear out the enemy instead. Brutus disagrees with Cassius, arguing that Antony and Octavius’s army grows stronger every day, while Brutus and Cassius’s army is already at its full strength, which must be seized like the “tide in the affairs of men, / Which, taken at the flood, leads on to fortune.”

Relenting to Brutus’s point of view, Cassius leaves. Brutus asks Lucius, Varro, and Claudius to stay in his tent so he can send Cassius a message if necessary. As the others fall asleep, a restless, sleepless Brutus begins reading to calm his mind. Caesar's ghost enters the tent, leaving Brutus disoriented and petrified. Brutus asks the ghost who and what it is “that makest [his] blood cold and [his] hair to stare.” The ghost cryptically replies, “Thy evil spirit, Brutus.” It tells Brutus it will see him again at Philippi and vanishes. Brutus wakes up Lucius, Varro, and Claudius, who tell him they did not see anything. Brutus asks Varro and Claudius to go to Cassius and tell him to begin mobilizing soldiers. Brutus's army will follow.

Analysis

What is most significant about the exchange between the triumvirate—Antony, Octavius, and Lepidus—is the commentary it offers on the cost of power. Antony’s portrayal in the first scene of act 4 is in marked contrast to the passionate rabble-rousing Antony of act 3. Here he is cold and calculating, drawing up a list of conspirators to execute, once again displaying his ability to switch gears when necessary. Significantly, he wants to redirect some of the bequests of Caesar’s will for his own ends. Thus, he is already backtracking on his promise to give seventy-five drachmas each from Caesar’s estate to the people of Rome. Antony’s reference to Caesar as a piece of earth now acquires double significance: Antony is fighting as much to gain control of that “bleeding piece of earth,” the Roman empire, as to avenge Caesar. His dismissal of Lepidus as a “slight, unmeritable man” and an “ass” who bears gold shows his calculating nature.

While the triumvirate is gathering strength, the conspirators are growing apart, prophesying the direction in which the wind is blowing. A new coldness has crept up between Brutus and Cassius, who now probe each other’s moods via messengers before meeting in person. The breach also recalls Antony’s curse of “civil strife,” which in this case can be taken to mean a war between friends. Already, the curse is breaking through the ranks of the conspirators, a sort of dying which is reinforced by the use of death imagery. For instance, Brutus notes that Cassius’s empty formality is that of

A hot friend cooling. Ever note, Lucilius,
When love begins to sicken and decay
It useth an enforcèd ceremony.

Brutus’s accusation that Cassius has an “itching palm” highlights the isolation of Brutus’s lofty principles in the world of realpolitik. Though Rome has been purified by the death of Caesar, Brutus is no closer to his ideal world than before. In fact, the petty behavior of Cassius only serves to highlight that perhaps Brutus alone among the conspirators was guided by the “general” cause. The last scene of act 4 heightens the pathos of Brutus’s character, deepening the sense of him as a tragic hero. After he and Cassius reconcile, he tells Cassius of Portia’s suicide, a sorrow he tries to drown in wine. The appearance of Caesar’s reproachful ghost is perhaps an outward projection of Brutus’s guilt. Ironically, the supernatural element symbolizes Brutus’s return to reality. He now understands the enormity of his crime and its consequence, as well as the truth about his perfect, noble enterprise. As earlier in the play, signs and supernatural visions point to a troubled fate for their recipient.