It's been a while since Inspector Amaia Salazar confronted her mother. However, despite the conclusion reached by both the Civil Guard and Judge Markina, Amaia feels that she is not free from danger. The sudden death of a girl in Elizondo raises suspicions, and forensic analysis leads Amaia to investigate other deaths with a similar origin, which will ultimately lead the inspector to the final resolution of the events that have plagued the Baztán Valley.