Various senators stab Caesar in the Capitol. The play’s opening scene foreshadows Caesar’s controversial standing. The commoners celebrate Caesar’s victory over Pompey, but several tribunes condemn them for being so fickle. Though they now rejoice over his defeat, the plebeians greatly admired Pompey when he was alive. The adulation of Caesar continues at the Feast of the Lupercal, where Marc Antony offers Caesar the crown three times.
Brutus, Cassius, and several other senators worry about Caesar’s growing power. They conspire to assassinate him in the senate. Brutus, who is good friends with Caesar, justifies the murder on the principle that power corrupts. They must preempt Caesar’s power grab to preserve the Republic of Rome:
And therefore think him as a serpent's egg
Which, hatch'd, would, as his kind, grow mischievous,
And kill him in the shell.
Caesar wonders whether he should go to the Capitol on that fateful day. His wife Calpurnia has nightmares about his death, and there are “most horrid sights” in the streets. Several priests sacrifice an animal but cannot find its heart. However, conspirator Decius Brutus convinces Caesar that Calpurnia’s dreams are fortuitous, tempts him with the crown, and suggests he will be mocked if he exhibits weakness.
Caesar calls Calpurnia’s fears “foolish” and goes to the senate. He ignores the warning of a friend and refuses to pardon Metellus Cimber’s brother in an attempt to demonstrate strength. The conspirators kneel to him, but Caesar asserts that he is not changeable like other men but as “constant as the northern star.” The conspirators, including Brutus, stab Caesar until he falls, dying on his famous line, “Et tu, Brute! Then fall, Caesar.”