ACT III. Eboli, who mistakenly believes that Don Carlo loves her, has written a letter to him asking him to meet her secretly. Thinking the note is from the queen, Don Carlo awaits her arrival in the palace gardens. When Eboli enters, heavily veiled, Don Carlo declares his love, but when she unveils, both realize their mistake. Eboli accuses Don Carlo of loving the queen. Rodrigo comes upon them, and, grasping the situation, tries to placate Eboli. She runs from the garden swearing to expose Don Carlo and Elisabetta. To protect the prince, Rodrigo takes his incriminating papers.
In the plaza before the Cathedral of Our Lady of Atocha in Madrid, an immense crowd waits for
Filippo and an auto-da-fé, a burning of heretics. Filippo emerges from the cathedral with the queen and is greeted by six Flemish deputies, led by Don Carlo. They are joined by the court and the people in begging for the king's mercy for the rebellious province, but friars insist on severe punishment. Don Carlo draws his sword on his father, who orders him disarmed. Don Carlo surrenders his sword to Rodrigo and is arrested for treason, while Rodrigo is made a duke on the spot. A group of heretics is led to the stake, and a celestial voice welcomes their souls into heaven.
ACT IV. Filippo spends a sleepless night in his study, reflecting on affairs of state and on his inability to make his wife love him. He consults with the Grand Inquisitor, who upbraids the king for allowing heretical ideas to creep into Spain. The Inquisitor consents to a death sentence for Don Carlo and insists Rodrigo be handed over to the Inquisition as well. As the ancient priest leaves, Filippo wonders if the throne must always yield before the altar.
Elisabetta bursts in, crying that her jewel box has been stolen. Filippo hands it to her and demands she open it. When she hesitates, he breaks it open and finds the portrait of Don Carlo. He accuses her of adultery. The queen faints, and Filippo calls for aid. Eboli and Rodrigo rush in, Rodrigo expressing amazement that this king who rules half the world cannot govern his own emotions. Rodrigo realizes that it is time to sacrifice himself for Don Carlo and the good of the nation. After the men have left, Eboli confesses that it was she who stole Elisabetta's jewel case, out of jealousy over Don Carlo, and gave it to the King. She then admits that she has been the King's mistress. Elisabetta banishes Eboli from Spain. The princess laments her fatal beauty and swears to spend her final day in Spain trying to save Don Carlo.
In Don Carlo's prison, Rodrigo says goodbye to his friend and tells him that Elisabetta will meet him one last time at St. Just. When a shot rings out, Rodrigo falls, mortally wounded. As he dies, he urges Don Carlo to save Flanders and be a new light for Spain. Filippo enters and returns Don Carlo's sword, but Don Carlo accuses him of Rodrigo's murder. The citizens storm the prison, demanding Don Carlo's release, and the disguised Eboli urges him to flee. The Grand Inquisitor appears and commands the rebellious crowd to kneel in obedience before Filippo.
ACT V. At the monastery of St. Just, Elisabetta waits for Don Carlo and prays at the Emperor's tomb. Don Carlo enters, and she inspires him to continue Rodrigo's quest for freedom in Flanders. They vow that their love will be rewarded in heaven, but Filippo interrupts them, accompanied by agents of the Inquisition. Filippo and the Inquisitor think they hear the voice of the dead Emperor, and the mysterious monk opens a gate and draws Don Carlo into the protective shadows of the cloister.
Elisabetta and Don Carlo, above (Poplavskaya, Roberto Alagna as Don Carlo)
© Beatriz Schiller 2013