July 2019. Vitoria-Gasteiz, Basque Country (north to Spain). Unai López de Ayala is a member of the Ertzaina (Basque Country's police) expert in criminal profiles who returns to the service after an administrative discharge due to the recent death of his pregnant wife in a car crash happened a year ago. His arrival to the commissary matches with the apparition of a pair of corpses whose criminal firm is the same of Tasio Ortiz de Zarate, a former TV host of a mystery show named "Telúrico" who was arrested by a serial of identical crimes 20 years ago that always claimed his innocence. Working with his partner Estíbaliz Ruiz de Gauna, a young woman with a trouble of drugs addiction after her brother, herbalist Eneko, Unai meets the newcomer deputy chief Alba Díaz de Salvatierra, who helps him as confident and friend when they both do night running by the city, feeling attracted each other to despise Estíbaliz and despite Alba is a married woman with journalist Mario Santos. Dividing his time between the job and his family life with his aging grandfather, his dwarf younger brother Germán and Germán's girlfriend Martina, the investigation forces Unai and Estíbaliz to interview Tasio in the jail as well as his twin brother and businessman Ignacio looking for new clues while new victims appear in the most important places of Vitoria as a personal challenge for Unai, after the killer writes him anonymously in an Internet's web. Trying to catch him, Unai and Estíbaliz investigate the past of the victims and the twins not knowing that the killer is the own Mario, a man with a dark secret of the past that silently moves by the city and between the police to mislead the investigation, ready and determined to fulfill his plan until the last consequences no matter who die in the way.