The thirteenth apostle

Gabriel Antinori is a Jesuit theology professor assigned to investigate alleged paranormal phenomena. He is also haunted by a past he can't remember. Orphaned, he grew up under the tutelage of Monsignor Demetrio Antinori, the uncle who entrusted him with his first case. Gabriel and Claudia find themselves investigating a case of alleged hemolacria: a young student at Santa Dorotea, a private all-girls boarding school, is crying blood. Gabriel unexpectedly discovers that the phenomenon is linked to a series of drawings that will sow terror and death within the school.

Shocked by the way Gabriel saved Agata, and unable to come up with rational answers, Claudia decides to investigate her past. Demetrio, on the other hand, refuses to believe his nephew, attributing his power to mental tricks caused by stress and an obsession with his past. Stefano, a sixteen-year-old boy, following a physical trauma, begins to have memories that seem to belong to a Nazi soldier. These memories replace his own, stealing his history and personality. Gabriel and Claudia find themselves investigating this unusual phenomenon, which does not appear to be attributable to mental illness.

In a remote village, Rachele, a young girl, returns after ten years, identical to the day she disappeared. Time seems to have stood still for her, but her presence, far from being miraculous, is accompanied by a series of mysterious deaths. Gabriel investigates the secret surrounding her return. The death of Marshal Marini and the return of Muster, who spurs Gabriel to delve deeper into the nature of his gift, lead Gabriel to the agonizing decision to return to the villa where he spent his childhood and where his mother lost her life. Gabriel asks Claudia to accompany him on this difficult journey.

Waking up in Gabriel's parents' villa is filled with disturbing memories. Gabriel is certain he saw his father's ghost and is convinced he died differently than his uncle had always told him. However, his thoughts also converge on the kiss he and Claudia shared that same night. Rosa, a forty-year-old woman confined to a wheelchair due to a spinal cord injury, inexplicably walks again. Yet, behind the apparent miraculousness of the phenomenon, disturbing implications loom. Gabriel will be forced to ask himself the same questions regarding his own gift.

The photos taken by Pietro reach the Directorate and compromise Gabriel's appointment, so much so that they manage to have him removed from the Congregation's new investigations, which are entrusted to Father Isaia. Gabriel, far from Claudia and the Congregation, is free to delve deeper, even into his own feelings. The case Gabriel investigates underscores the fact that the past must always be confronted, not erased: in an elegant Roman home, a woman senses the presence of a ghost haunting her, one she can't name. But what terrifies and unsettles doesn't always come to destroy.

Arriving in time to save Claudia, Pietro will pay the ultimate price for his heroic deed. Blinded by grief, Gabriel realizes that there can only be one person behind Claudia's attack, the only one to whom he had confided where they were going: Isaiah. While Demetrio delivers Isaiah to the Candelaio, Serventi mercilessly interrogates Alessandro Foschi, aiming to discover where he has hidden the anti-gospel that would allow Gabriel to anticipate his moves. Foschi, however, wants Gabriel to know everything, so he can finally choose who he is, and so decides to remain silent.