what does lucius perform that helped the plot to unfold
In Act II, scene i, Brutus is found pacing in the garden, troubled by his thoughts of Caesar and the possible ramifications of Caesar's reign, once crowned. It is while Brutus is pacing that Lucius brings Brutus several letters written by contemporaries of Brutus, all urging Brutus to act against Caesar, and to act quickly. These letters, left by Cinna according to the wishes of Cassius, prompt Brutus into agreement with the other conspirators, and Brutus ends up as the leader of the band of plotters. These letters provide the impetuous to finally drive Brutus to action, and to joining the conspirators.