Orcano is still angry with his daughter and threatens her with the sword. Siface protects her, however, and Ismene leaves. Siface then affirms that he wants to marry Ismene and that Viriate had betrayed him. As proof, he shows him a fake letter from Viriate to Erminio. In it she writes about their love and their plan to murder Siface. Orcano secretly doubts the authenticity of the letter.
