Cassius' conspiracy gains momentum when he recruits a suspicious Casca to their cause against Caesar by pointing out that several recent strange occurrences are omens warning them against Caesar... To ensure Brutus joins his conspiracy, Cassius has Cinna place some forged letters where Brutus will find them convincing Brutus to join their cause. Cinna reveals that Brutus' good name will be an asset to their conspiracy...
Act II.
Brutus cannot sleep, revealing for the first time his own true fears that Caesar may be growing too powerful. A letter is discovered, which Brutus reads, convincing him to join the conspiracy. The complete group of conspirators meets at Brutus' house, discussing Caesar's assassination. Brutus argues against Caesar's right hand man, Mark Antony being assassinated as well. Cassius and Trebonius have their doubts but go along with Brutus. Brutus' troubled wife Portia tries to find out what her husband is planning worried for him...
Calphurnia, Caesar's wife, wakes Caesar up after herself awakening from a terrible nightmare. She tells Caesar, that her dream foretells doom and succeeds in convincing Caesar not go to the Senate (also referred to as The Capitol) on the "ides of March" which is tomorrow. Decius Brutus arrives and hearing that Caesar will not be at the Senate tomorrow, flatters Caesar into going so as not to show fear (allowing Brutus and company to kill him there).
Artemidorus waits in a street with a letter warning Caesar of the conspiracy, hoping to avert Caesar's assassination...
Portia worries for her husband, hoping his "enterprise" today will succeed. The Soothsayer, who warned Caesar about the "ides of March" in Act I, waits in a narrow street hoping to warn Caesar of his imminent danger...
Act III.
Caesar arrogantly tells the Soothsayer that today is the "ides of March", but the Soothsayer tells him the day is not over yet... Artemidorus nearly warns Caesar but Decius Brutus prevents this. Popilius wishes the conspirators good luck, scaring them that Caesar may already know their plans.
Metellus Cimber petitions Caesar to lift his brother's banishment order. Caesar refuses and the conspirators kill Caesar. Mark Antony flees. Mark Antony pretends to treat Caesar's murderers as friends. He asks to speak at Caesar's funeral. Cassius thinks this is dangerous, Brutus, disagreeing, lets Mark Antony speak at the funeral.
Mark Antony reveals his true hatred for the conspirators. Octavius, Mark Antony's ally is remain safely outside of Rome a little longer... Brutus and Cassius explain to the citizens of Rome why they killed Caesar, gaining their support.
Using the immortal words, "Friends, Romans, countrymen, lend me your ears;" Mark Antony turns the citizens of Rome against Brutus and Cassius by making the citizens feel remorse for Caesar's cruel death and by bribing then with the news that Caesar's will gifts each citizen money from his will. Mark Antony uses this fact to suggest Caesar was a great man who should not have been murdered.
The crowd, now an angry, crazed mob, go after the conspirators including Brutus and Cassius who flee in fear...
A poet called Cinna who bears the same name as one of the conspirators is killed by the angry mob which shows Shakespeare's insight into the senselessness of the mob mentality...