The scene shifts briefly back to Caesar's camp. Sentries are keeping watch throughout the night, and they hear Enobarbus, still distraught, speaking to the moon. In a moving soliloquy, Enobarbus makes his final speech; he is a symbol of melancholy and madness, and he despairs that he deserted Antony. As he falls and dies, probably of self-inflicted wounds, the sentries go to him, thinking that he has merely fainted. When they discover that he is dead, they carry his body back to the camp.
It is theatrically fitting that Enobarbus's final irrational despair and delirium should occur in a scene bathed in moonlight. Many people in Shakespeare's time believed that night air and moonlight could cause illness, depression, and even madness. Even now we have words based on such notions — "moonstruck," "lunatic," and "looney," for example. It is not clear from the stage instructions whether Enobarbus falls on his sword or whether he simply dies of self-inflicted wounds. Perhaps he has already stabbed himself, and we are hearing his last words. It is possible, however, that "the flint and hardness" of his fault is figurative only, and that he dies of grief and of a broken heart.