L'incoronazione di Poppea
Nero tells Seneca that he is going to get rid of his wife and marry Poppea.  Seneca warns Nero that the people will not like this, but Nero does not care.  He is emperor and can do what he likes.  Nero tells Poppea that he loves her so much that he wants to make her empress.  Poppea says to Nero that Seneca believes that Nero is only powerful because he (Seneca) can guide him.  Nero immediately believes her and says Seneca should be killed.  Otho has been watching this scene.  He goes to Poppea and tries to get her love back, but Poppea says she belongs to Nero now.  Otho realizes that Poppea just wants power, and he knows that Nero will order him to be killed when he finds out that he used to be Poppea’s lover, so he decides he will have to kill Poppea.