Afonso is arrested. Petronio and Orlando are petrified in front of Brice. Martinho informs Amália that, in Augusto's absence, the princess is the only one who can free Afonso from prison. The mandingueira called by Rodolfo explains to the king that only a man with a pure heart can expel Brice from the castle. Catarina disregards Demétrio's recommendations and decides to treat Afonso as a normal prisoner.