In an army camp near Sardis, Brutus, Lucius, Lucilius, and other soldiers meet Titinius and Pindarus.
Brutus talks with the others about a disagreement with Cassius.
Aside, Brutus tells Lucilius that Cassius is starting to seem fake and overly courteous, and that he doesn't trust him like he used to.
Cassius arrives and accuses Brutus of having done him wrong.
Brutus, surprised, says that he doesn’t even wrong his enemies, so how could he wrong a “brother”?
Cassius reacts impatiently. They withdraw to Brutus’s tent so that the army won’t overhear their argument. Lucilius and Titinius stand guard.