: The constant rain and the thick, gloomy forests of the Navarre region serve as a character themselves, heightening the "noir" feel.

: The plot constantly blurs the lines between a modern investigation and ancient legends. The Basajaun , a protector of the forest in Basque mythology, becomes a central figure of both local superstition and the killer's identity.

The narrative follows , an FBI-trained police inspector who returns to her rainy hometown of Elizondo to investigate a series of ritualistic murders. Young girls are being found dead along the banks of the Baztán River in poses that suggest a macabre ceremonial intent.

: The story deeply explores family dynamics, specifically the powerful and often suffocating influence of the women in Amaia’s family.