Amaia Salazar’s investigation shifts from isolated infant deaths to the possibility of a shared human cause when she links several families to an old secret group and to the midwife Fina Hidalgo. The connection is not established by a single decisive proof: it emerges through a cluster of suspicious circumstances, missing records, professional access to births, and a disturbing statement attributed to Fina. The distinction between a medical label and a proven explanation becomes central as Amaia tests what the families have been told against what the records and witnesses can support.

From a medical diagnosis to a pattern

The inquiry begins against the background of sudden infant death syndrome, a diagnosis applied to the unexpected death of a child, usually under one year old, during sleep and without apparent signs of distress. Amaia learns that it is an exclusionary classification: it is used when an autopsy finds no other cause that explains the death. The diagnosis therefore describes what the examination has failed to establish, rather than identifying a precise mechanism. In Navarra, seventeen children had died under that classification during the previous five years, four of them in the local valley; the figures were consistent with the broader European average. The numbers alone do not prove a crime, but they show why a death recorded as sudden infant death could pass without attracting unusual attention.

A review of earlier cases adds a more specific warning sign. Every case had received an autopsy and the same classification, yet social services had later investigated two of the families. Those inquiries appeared to have ended without further action. That history does not establish that the deaths were connected, but it gives Amaia a reason to look beyond the official diagnosis and compare the families’ circumstances rather than treating each death as a closed medical event.

The death of Valentín Esparza’s daughter supplies a concrete forensic contrast. Doctor San Martín found that the child had been suffocated while asleep: the pressure mark on her face matched the nose of a teddy bear, and white fibers at her lips came from the toy. Saliva on the child and the bear included a trace attributed to Valentín. These findings concern that particular death, not proof of Fina Hidalgo’s involvement. Their importance to the wider inquiry is that they demonstrate how a death associated with sleep can require close examination of physical evidence, even when other infant deaths have been routinely classified as sudden.

The old group and Ainara’s missing records

Amaia’s account to her colleagues brings the investigation back to Elena Ochoa, a family friend who had described a group based at a farmhouse in Orabidea in the late 1970s and early 1980s. The group had begun as a commune holding cultural and spiritual gatherings before moving toward occult practices and animal sacrifice. Elena left after the rites became more violent; the possibility of human sacrifice had also been raised. Amaia believes the group’s history may explain why Rosario Salazar and Doctor Berasategui disappeared together for a period before the attack on her family, and why Berasategui had been seen at the renovated farmhouse occupied by two former members.

The couple’s daughter, Ainara Martínez Bayón, gives that suspicion a documentary test. Her parents said that she had died of a stroke at fourteen months while the family was travelling in the United Kingdom, and that she was buried there. But the inquiry found no British hospital record, death certificate, or autopsy record for her. Amaia’s colleague also found no evidence that the child had been taken out of Spain or that her death abroad had been reported to the Spanish embassy. The absence of those records does not by itself establish what happened to Ainara; it does undermine the account her parents gave and makes the family’s earlier infant death relevant to the pattern.

The connection to the former group is supported by testimony as well as by the family history. A neighbor identified Berasategui’s car at the property on more than one occasion, and the couple acknowledged knowing him, although they would not explain the relationship. When Amaia asked about their dead daughter, their reaction was markedly different from their response to questions about the doctor. She therefore asks her team to establish whether the families connect through the lawyers, Berasategui, or the couple, and assigns Jonan Etxaide to pursue the records concerning Ainara.

Fina Hidalgo becomes the suspected link

Amaia’s next step is to search for a person who could connect births across families. She identifies Fina Hidalgo, a private midwife and the sister of Doctor Hidalgo, a rural physician who had served families throughout the valley. Fina had attended Amaia’s own birth and the birth of her twin sister, who died in infancy. Her brother signed the death certificate. Amaia also suspects that Fina attended the other births under scrutiny, including the births of children whose deaths had been classified as sudden infant death.

The Esparza case complicates, but does not eliminate, that theory. Fina was retired from hospital work, yet she continued to practise privately. Valentín had brought her to his home and tried to persuade his wife to give birth there; she was therefore connected to the family without having attended the child’s hospital birth. Amaia stresses that she cannot yet confirm Fina’s presence at every relevant birth. She would need authorization to examine Doctor Hidalgo’s private records and the death records in order to establish whether Fina had attended them. Her proposed connection remains an investigative hypothesis, not a conclusion already demonstrated by the available documents.

Amaia’s strongest indication of Fina’s possible motive comes from a conversation the two women had previously held. Fina had acknowledged that, when children were not healthy or normal, families sometimes had to be helped to free themselves from the burden of raising them. Amaia hears in that remark the rationale associated with an Angel of Death: a caregiver who regards killing as a benevolent service. Yet the remark has no independent witness, and Amaia says no one else heard it. Its force in the investigation comes from the way it fits the access and family connections she is tracing, not from its being corroborated testimony.

What the connection changes

The emerging pattern joins cases that had initially appeared to be separate tragedies: Amaia’s twin sister’s death, other infant deaths in families associated with the farmhouse and its former group, and the death of Esparza’s daughter. The parents’ conduct and the social-services follow-up in some cases had already attracted notice, but the common links make those details newly consequential. The investigation also raises the possibility that a familiar medical classification could conceal very different circumstances from one family to another. Amaia does not treat the classification itself as evidence of murder; she treats it as a reason to ask what the autopsies, records, and relationships do—and do not—show.

The later testimony of Yolanda Berrueta sharpens the stakes of that distinction. A priest who knew her family had believed her children were buried in their cemetery because he had officiated at the funeral and watched the coffins lowered into the grave. Yolanda continued to insist that their bodies were gone. After Amaia’s error led to the order to open the tomb being stopped, Yolanda explained that proving her children were present would have left the missing girl undiscovered and her own warnings dismissed as madness. Her account makes the search for physical confirmation more than a procedural issue: an apparently settled burial can preserve a false explanation and silence the person who senses that something is wrong.

The suspicion around Fina thus grows through cumulative links rather than a single revelation: repeated attendance at births, a physician’s records that may clarify who was present, families connected to the old group, an account of Ainara’s death unsupported by the expected records, and Fina’s own disturbing statement. The later discovery that a baby’s body had indeed been stolen from a grave confirms that at least one family’s fear of missing remains was not delusion. By the time the dangerous group is exposed, Elena Ochoa’s warning has helped direct attention toward a network rather than a succession of isolated bereavements. The event’s significance lies in that change of scale: infant deaths once recorded as separate misfortunes become questions about access, concealment, and the possibility of organized violence.