It is the banqueting hall of the castle.  The Pontifical divorce is spread upon the table.  Courtly friends, guards, and a choric bridal company, form a circle.

‘I have obtained it,’ says Count Orso:  ‘but at a cost.’

Leonardo, wavering eternally, lets us know that it is weighted with a proviso:  If Camilla shall not present herself within a certain term, this being the last day of it.  Camillo comes forward.  Too late, he has perceived his faults and weakness.  He has cast his beloved from his arms to clasp them on despair.  The choric bridal company gives intervening strophes.  Cavaliers enter.  ‘Look at them well,’ says Leonardo.  They are the knights of the plains.  ‘They have come to mock me,’ Camillo exclaims, and avoids them.

Leonardo, Michiella, and Camillo now sing a trio that is tricuspidato, or a three-pointed manner of declaring their divergent sentiments in harmony.  The fast-gathering cavaliers lend masculine character to the choric refrains at every interval.  Leonardo plucks Michiella entreatingly by the arm.  She spurns him.  He has served her; she needs him no more; but she will recommend him in other quarters, and bids him to seek them.  ’I will give thee a collar for thy neck, marked “Faithful.”  It is the utmost I can do for thy species.’  Leonardo thinks that he is insulted, but there is a vestige of doubt in him still.  ’She is so fair! she dissembles so magnificently ever!’ She has previously told him that she is acting a part, as Camilla did.  Irma had shed all her hair from a golden circlet about her temples, barbarian-wise.  Some Hunnish grandeur pertained to her appearance, and partly excused the infatuated wretch who shivered at her disdain and exulted over her beauty and artfulness.

In the midst of the chorus there is one veiled figure and one voice distinguishable.  This voice outlives the rest at every strophe, and contrives to add a supplemental antiphonic phrase that recalls in turn the favourite melodies of the opera.  Camillo hears it, but takes it as a delusion of impassioned memory and a mere theme for the recurring melodious utterance of his regrets.  Michiella hears it.  She chimes with the third notes of Camillo’s solo to inform us of her suspicions that they have a serpent among them.  Leonardo hears it.  The trio is formed.  Count Orso, without hearing it, makes a quatuor by inviting the bridal couple to go through the necessary formalities.  The chorus changes its measure to one of hymeneals.  The unknown voice closes it ominously with three bars in the minor key.  Michiella stalks close around the rank singers like an enraged daughter of Attila.  Stopping in front of the veiled figure, she says:  ’Why is it thou wearest the black veil at my nuptials?’

‘Because my time of mourning is not yet ended.’

‘Thou standest the shadow in my happiness.’

‘The bright sun will have its shadow.’