1.2: At the feast of the Lupercal, Brutus acts like a party pooper and says he can't help it – he's just not as much fun as some people...like Antony. Plus, he's been upset about something lately and is "at war" with himself.
1.2: Before heading home, Brutus chats it up with Cassius, who tries to convince Brutus that Caesar is bad for Rome and needs to be offed. Brutus should totally join the conspirators against Caesar. Brutus plays coy and says he'll think about it.
2.1: Brutus reasons with himself in his garden late at night. He concludes that he must help take down Caesar, who could become a tyrant if he's given too much power.
2.1: Brutus reads a bunch of letters supposedly written by some concerned Roman citizen (they're really written by Cassius) about Caesar's growing power.
2.1: Brutus then welcomes all the conspirators, and as Cassius suggests they swear an oath, Brutus gives a rousing speech about how killing Caesar is the right thing to do.
2.1: Brutus meets a concerned Portia and tries to convince her that he's just not feeling well. She pleads with him to let her know what's bothering him. He promises she's his true wife (meaning that he loves her), and after listening to her beautiful speech about being a noble daughter and a noble wife, he cries out to the gods that he hopes to be worthy of her. He's interrupted by a knock and sends her to bed, promising he'll share his burden with her eventually.
3.1: Brutus participates in stabbing Caesar until the guy looks like a bleeding fountain.
3.1: Brutus agrees to let Antony speak at Caesar's funeral, on the condition that Antony not blame the traitors but speak only good of Caesar.
3.2: Brutus delivers a speech about Caesar. Prophetically, he promises he has done no more to Caesar than the Romans will do to him (Brutus). He closes with the fact that he "slew his best lover" (not in a romantic sense) for Rome, and that he will use the same dagger he killed Caesar with on himself when his countrymen want his death. (It's like he's psychic!) He then excuses himself from hearing Antony's speech, which is probably not a good idea.
4.2: Planning the battle against Antony, Brutus confides in Cassius's servant Pindarus. He says Cassius's actions since the murder have been shady and make him wish they have never started down this path. Still, he'll wait until Cassius arrives to clear it all up. Brutus also tells Lucilius that he fears Cassius's friendship is cooling, which can't be a good sign.
4.3: Brutus and Cassius argue about Cassius's acceptance of bribes, and Brutus condemns him for being greedy. Worse, he thinks this undermines their assassination of Caesar. If they begin to support robbers, he says, they can't claim they killed Caesar out of justice.
4.3: The fight escalates, and when it comes to a head, Brutus warns Cassius that he'll be sorry. Brutus has no fear because he's strong in his honesty. (Again, he thinks he's protected by his own integrity, which is admirable but not so smart.) Then they go back to fighting again: Cassius denied Brutus gold for his troops, and Brutus wouldn't pinch it from the poor peasants. This continues until Cassius, in a fit, offers himself up for Brutus to stab, since Brutus thinks he's such an awful guy.
4.3: There are apologies all around, and the men leave the tent as friends willing to put up with each other's tempers. Before they exit, though, Brutus cryptically says Cassius is "yoked with a lamb that carries anger as the flint bears fire," meaning something else is up that's the real foundation of Brutus's bad mood.
4.3: Brutus admits what the lamb is: Portia's recent death, which has added to his sorrow. He explains that she died of grief over his absence. He doesn't want to talk about her anymore and demands that no one else does. Then he takes a drink to soothe his feelings.
4.3: Brutus now confers with Messala, who has arrived with some news from Rome. The two discuss what Antony and Octavius are up to in Rome, then Brutus asks Messala what news there is of Portia. Once he gets Messala to admit Portia is dead, he simply says farewell to her. She had to die sometime, and he can endure the thought of her death now that it has passed.
4.3: Brutus quickly gets back to business. The men debate whether they should meet the enemy at Philippi or wait for the enemy to come to them. Brutus makes a case for the former: they're at their most powerful now and can only become weaker, he argues. If they act now, fortune might carry them, but if they wait, they're doomed.
4.3: Brutus, content that everyone (including Lucius, the musician) has gone to bed, cracks open his book. Just then he sees the ghost of Caesar, which makes his "blood cold." He asks what it has come for, and hearing it say they'll meet at Philippi, he becomes brave Brutus again. He bids the ghost a terse good-bye, saying fine, they'll meet at Philippi then. Brutus wakes everyone else up to ask if they saw anything. Hearing that they didn't, he sends messengers to tell Cassius they should deploy their armies early.
5.1: Brutus is now at the battlefield with Cassius. They challenge Antony and Octavius before the battle begins. Brutus asks if they'll have words before blows, which seems mocking, because he would like to get straight to the point and not mess around. Octavius and Antony taunt him, but Brutus keeps his cool before he goes back to his men.
5.1: In veiled terms, Brutus and Cassius confer over what they'll do if this is their last meeting. While Brutus thinks suicide is cowardly, he admits, upon Cassius's reminder, that he will never go to Rome in bonds of defeat. He then pronounces that the work they began on the Ides of March will come to an end today. Brutus says goodbye to Cassius, just in case this is it, and he doesn't let on whether he thinks they have a chance. Brutus is neither proud nor cowardly. He follows Cassius into battle, the very picture of stoicism. They don't know what the day will bring, but they know that it will end, and when it does they'll have the answer.
5.3: Brutus has advanced his troops on Octavius's weak spot. Now he goes to see the body of Cassius, whom Messala told him has died. Seeing Titinius dead too, Brutus cries out to Caesar's spirit, saying it is mighty still, as it makes men kill themselves.
5.3: As Brutus looks over the bodies of Cassius and Titinius, he declares there shall never be more Romans like them; he calls them the last of all the Romans. Brutus says his friends won't see him shed all the tears he owes Cassius, but he'll find time eventually to mourn. Back to business, Brutus sends the bodies away from the camp to be buried so they don't disturb the men. He calls all his remaining men back to the field to try their luck again.
5.5: Brutus stops to rest with the remainder of his men. He pulls each of them aside separately and asks them to kill him. To the last man, Volumnius, he admits he saw the ghost of Caesar at Sardis and again on the battlefields. He says he knows his time has come. He would rather jump into the pit of death than wait for his enemies to push him in, and he hopes Volumnius, out of love, will help him take his own life.
5.5: Brutus says good-bye to his men and promises to follow them as they flee from the enemy. Then he declares that he finds more glory in this losing day than Antony or Octavius shall have through their vile conquest. Brutus accepts death peacefully, saying his bones have worked their whole life for this hour's rest. Strato holds Brutus's sword while Brutus runs on it, proclaiming: "Caesar, now be still, I kill'd not thee with half so good a will."