Amaia discovers a link between the Basajaun and Tarttalo cases

Amaia discovers a link between the Basajaun and Tarttalo cases by shifting her investigation from the men who carried out the killings to the people who selected and shaped them. In a dawn conversation with Father Sarasola, she argues that Doctor Berasategui chose his victims, manipulated the men who killed them, and may himself have answered to a still-active cult network. Sarasola’s confirmation that Berasategui treated Víctor Oyarzabal turns that theory into a concrete investigative connection, though not yet a complete explanation of the crimes.

Background: An Older Network in Baztán

Amaia’s theory reaches back to the late 1970s and early 1980s, when a sect-like group established itself at a farmhouse in Orabidea. According to Elena Ochoa, who had attended some of its meetings with Amaia’s mother, the group began as a commune associated with cultural and spiritual gatherings before moving into occult practices and animal sacrifice. The suggestion of human sacrifice became intolerable to Elena, and she left, although the group continued for a time. Amaia also connects Rosario to this group and says its members had discussed sacrifices of newborns and very young children.

The older gatherings provide more than a historical parallel. At a briefing, Amaia described evidence of related practices at Argi Beltz in Baztán and at another farmhouse in Lesaka. An informant had described a single leader moving between the groups, while Elena’s account and the informant’s report both connected a child’s birth and suspicious death to Argi Beltz. The child was Ainara Martínez Bayón, whose parents claimed she had died abroad. The investigation had found no supporting record of a British death, hospital treatment, or burial. Amaia also named people who had attended the gatherings, including Doctor Berasategui, Nurse Hidalgo, and Valentín Esparza. These associations raised a question about a network crossing households and locations, but association alone did not establish what each person had done.

Reframing the Victims

At the cathedral in Pamplona, where she meets Father Sarasola before the first morning mass, Amaia explains how her understanding of Berasategui has changed. She describes him as an unusually sophisticated instigator: a psychiatrist with access to people’s behavioral disorders, able to use their anger and persuade them to commit extreme violence. The men who killed the Tarttalo victims, in her account, acted out a work directed by Berasategui. He then took his own trophy from the dead women, amputating an arm and collecting it in a cave associated with the creature whose name he adopted.

The decisive shift in Amaia’s reasoning is that Berasategui did not merely find vulnerable men; he selected the women they would kill. The Tarttalo victims were women of Baztán origin, even when they no longer lived in the valley or died far away. Amaia sees a pattern in their later treatment too: the women were stripped of signs of adulthood and presented as childlike offerings to purity and tradition. She compares them with the adolescent victims found in the river. This parallel does not make the cases identical, but it leads her to suspect that the choice of victims belongs to a wider ritual logic rather than to the killers’ private impulses alone.

The Connection to Basajaun

Amaia traces Víctor Oyarzabal’s vulnerability through what she knows of his life. He had a dominant mother and repeated that pattern when choosing his wife. He began drinking young in an effort to control his murderous impulses and later told Amaia that he attended therapy in Irún. She had assumed the therapy might have been connected with a local Alcoholics Anonymous group, but Oyarzabal specified a discreet therapy group. That detail prompts Amaia to ask Father Sarasola whether Berasategui’s encrypted clinical files recorded Oyarzabal’s treatment.

The files mattered because they reportedly documented every case Berasategui handled, both at the clinic and in private practice, including the Esparza case. Father Sarasola said he did not possess them: after Berasategui’s arrest in connection with Rosario’s release and the Tarttalo crimes, the highest Vatican authorities had taken an interest. Amaia’s question about the files therefore joined a medical record system to the wider inquiry, but she still needed confirmation about Oyarzabal specifically.

Father Sarasola supplied it. When Amaia later told her colleagues that he had confirmed Berasategui treated Víctor Oyarzabal for anger control, she could connect the psychiatrist directly to the man known as Basajaun. Sarasola also confirmed that Berasategui had treated the other homicidal men implicated in their crimes. The link made Amaia’s theory firmer: the psychiatrist’s access to troubled men could have been the means by which he identified, directed, or exploited them. It did not by itself prove that therapy created their violent tendencies. Amaia’s distinction is that a destructive group can take a person’s existing obsessions and channel them, turning vulnerability into service.

What the Discovery Leaves Unresolved

Amaia refuses to regard Berasategui’s death as the end of the investigation. After reviewing clinic security footage, she felt that the explanation did not fit what she knew of him: when she interviewed him that morning, he seemed closer to escape than suicide. She therefore asks who induced him to die, just as she asks who ordered Rosario’s death. Her suspicion is that the cult had survived the decades since the farmhouse gatherings, perhaps becoming better connected and more experienced. This remains her conclusion and challenge to Father Sarasola, not a fact established by the conversation.

The exchange also exposes the limits of what she can prove. Sarasola’s confirmation gives her a crucial investigative lead, but he may deny the conversation if called before a judge. Amaia’s discovery is therefore both a recognition and an unfinished task: the Tarttalo and Basajaun cases now share a documented therapeutic connection, while the identity of any higher authority, the full extent of the group, and its role in Berasategui’s death remain open. By following the victims’ origins, the men’s treatment, and the older gatherings in Baztán, she turns apparently separate crimes into a pattern worth pursuing without mistaking the pattern for a solved case.