It is the religious feast of Lupercal. People are celebrating in the streets of Rome. They are celebrating because Caesar has just defeated his rival Pompey. Caeser now has a chance to take full control of the throne.
I must be a conspirator
Caesar attends the traditional race at the festival of Lupercal. While he is there he meets a soothsayer. The soothsayer tells Caesar "beware the ides of March." While all this is going on Cassius and Brutus are discussing what they are going to do about Caesar.
Caesar you must go to the capital
Ok i will
Casca notices the bad weather. He tells Cassius that it is a bad sign. Cassius declares that Caesar must be overthrown. Now they both agree that Caesar's rise to power shall be stopped by any means.
The conspirators send a letter to Brutus. They are trying to convince him to become a conspirator. They want him to help because he is close to Caesar.
Caesar was not going to go tho the capitol. because of this the conspirators needed to make him go. So they started saying things like "the people will think Caesar is weak." So Caesar fell into their trap and he went.
Caesar fell into their trap. he was killed by the conspirators. Antony was left wanting revenge.