The Question and Answer section for Julius Caesar is a great resource to ask questions, find answers, and discuss the novel.
The main conflict in Julius Caesar is Brutus' fear that Caesar plans to take over Rome and destroy the Republic. The solution (not Brutus' idea) is to assassinate Caesar.
Cassius has a few messages to Brutus. Please be more specific.
I think you might mean act 4 sc 2. The two men continue arguing, and Brutus finally tells Cassius that he is upset that Cassius refused to send him gold with which to pay his soldiers.