1. Tension: Following Caesar's assassination and Antony's potent oration, emotions are already running high. The conspirators are afraid for their lives and have retired to the capital, uncertain about their next steps. The tension in the air pallpable as it remains to be seen how the public outcry against them will unfold.
2. Fear: The people of Rome are gripped with fear and resentment toward the conspirators for disrupting their lives and challenging the established order. Fears are fueled by Antony's strategic use of rhetoric that portrays the conspirators as bloodthirsty tyrants. The crowd's fear manifests in their anger and readiness to turn against the assassins.
3. Uncertainty: Uncertainty looms large as to what the course of events will be. The republic's future hangs in the balance, with the conspirators on one side and Antony, Octavius, and Lepidus on the other. The atmosphere is tinged with uncertainty about who will emerge victorious in this power struggle.
4. Chaos: The streets are thrown into chaos as the rioting crowd sets fire to the conspirator's houses. The mob is uncontrollable and driven by a sense of vengeance. This chaotic situation further contributes to the sense of disorder and instability in Rome.
5. Foreshadowing: There is a sense of impending doom and foreboding as the play's end draws near. The mood is darkened by the realization that Rome's political landscape has been irreparably altered by the conspirator's actions, and the consequences are yet to be fully realized.
In summary, the mood at the end of Act Four in Julius Caesar is one of tension, fear, uncertainty, chaos, and foreshadowing. The play sets the stage for the intense culmination of events in the final act.