During the time that Schedoni and Ellena travel back to Naples, Paulo and Vivaldi remain imprisoned and are interrogated separately.

When Vivaldi is called to the Holy Office, he undergoes a longer examination as the inquisitors attempt to goad him into confessing crimes of which he is suspected in order to draw from him other crimes which may have eluded them. However, the examiners manage to withhold from him the chief accusation on which he was arrested.

On his way to the prison, Vivaldi notices a monk resembling the one he encountered at the fortress Paluzzi. He attempts to follow him but is prevented by the guard. When he questions the guard as to whether the monk is an inquisitor, the guard denies seeing him altogether. As they proceed along the hall, Vivaldi hears groans and is curious to know from where the sounds are emanating. The guard answers that they are passing by the torture chambers. At this point, the narrator explains that the officials had recommended that Vivaldi be conducted through this path so as to be persuaded to confess.

Vivaldi is called up for a third examination, followed by a fourth a few weeks later. Since there are no proofs of his innocence, and he persists in denying the charge and refusing to confess, he is threatened with torture. After being led through a number of passages at midnight, he finally arrives at a room where a Grand Inquisitor, Advocate of the Exchequer, and Ordinary Inquisitor are seated. As Vivaldi refuses to confess, the officials begin to prepare him for the rack. The preparations, however , are interrupted as an intruder—the monk who frequently accosted Vivaldi at Paluzzi—appears and begins to interrogate him on his actions at San Spirito and his acquaintance with Ellena. It is at this point that Vivaldi realizes that Schedoni was not the monk issuing warnings to him at Paluzzi.

During this examination, the Grand Inquisitor himself is surprised by the fact of an intruder posing questions. After being led back to his cell and falling asleep, Vivaldi dreams of the intruder before waking up and finding him by his side. The monk reveals several facts concerning Schedoni’s past life, claiming that Schedoni had a wife and brother and that a murder took place at some time. He instructs Vivaldi to summon Schedoni as well as Ansaldo, who will divulge the crimes confessed by Schedoni during the examination of the following evening. As Vivaldi hesitates, not knowing the truth of these assertions, the monk insists that he must obey.

Afterward, Vivaldi is mystified as he questions the sentinel about the intruder who entered his cell, only to be told that the sentinel has not seen anyone.