Ansaldo, Schedoni, and Vivaldi are now called before the holy office. Schedoni had already been arrested on his way to Rome in his efforts to free Vivaldi so as to prevent Vivaldi’s parents from learning about his predicament. Their discovery, he fears, might lead them to discover Schedoni’s role in the matter while also destroying the chances of a marriage between the two lovers. Their immediate nuptials, Schedoni believes, would make it less likely for Vivaldi to suspect the extent of his own role in sending him to the Inquisition.

Meanwhile, the motivation behind Schedoni’s arrest is unknown to himself, as he suspects he was called to account for his report on Vivaldi’s contempt for the Catholic faith when Vivaldi insulted him at San Spirito. At this point, he also believed he was sent in for the purpose of divulging details on Vivaldi’s guilt. However, he is not without suspicions that he may have been summoned by Vivaldi’s parents, although he finds it unlikely.

During this time, Schedoni and Ansaldo are questioned separately, with Ansaldo revealing the particulars of the confession he heard in 1752 at San Marco. At the interrogation with Schedoni and Vivaldi, he is asked to repeat the story for the purposes of discerning the reactions of Schedoni and Vivaldi at these disclosures. When the grand vicar asks Schedoni and Ansaldo if they know each other, Vivaldi is surprised to hear both men deny it, especially Ansaldo, even if Ansaldo is less sure and does not take an oath.

During his deposition, Ansaldo discloses that he heard some groans one evening issuing from the confessional of San Marco. He encouraged the person within to confess, noticing that the latter appeared to be under pressure from a tremendous sin that he struggled to keep hidden. The penitent confessed, pleading for absolution.

In love with his brother’s wife, the penitent (Schedoni) had murdered his brother. The murderer persuaded the widow to marry him. Although she agreed to the marriage out of convenience, she loathed him. One night, he discovered her with a lover and stabbed her; upon hearing this detail from the penitent, Ansaldo realized that the lover was none other than himself. While Ansaldo is speaking, Schedoni interrupts to ask if she was innocent, to which an affirmative is given. An inquisitor asks if Ansaldo recognizes Schedoni’s voice as that of the unknown penitent, to which he answers yes but that he is not entirely positive. Ansaldo adds that he was so shocked to discover the identity of the murderer that by the time he recovered, the penitent had already fled and was nowhere to be found by the other monks. Here, he remarks that even though he is certain of the identity of the Count di Bruno, he is unaware that he is one and the same with Schedoni.

At this point, the mysterious informer begins to interrupt, upon which Schedoni grows agitated. The informer asks Schedoni if he knows him, showing him the dagger with which he stabbed his brother. Schedoni is terrified, leaning against the pillar for support. Vivaldi points out that this informer was his secret visitor.

As Schedoni insists that he was not a murderer, the mysterious informer points to Ansaldo as evidence. In the meantime, Vivaldi confirms to the Grand Inquisitor that the mysterious informer is his visitor. When Schedoni is questioned in regard to the mysterious informer, he responds that his name is Nicola di Zampari. The monks had met when they belonged to the convent of San Angiolo. Nicola became embittered and resentful when Schedoni’s efforts to promote him at...