1934 Asturian miners rebel against their social situation and - in the belief that Catalonia, Andalusia and Madrid support them - they take up arms against the Civil Guard and the army, eventually conquering the capital: Oviedo. While these events are taking place, the Civil Guard coroner, in the absence of enough troops, must take the lead in the investigation and discovery of a serial killer. Each of the murders is associated with a mythological being from Asturian mythology. Two brothers from a humble mining family find themselves involved in the struggle of that red month of October. Pelayo will guide the miners to Oviedo, while David, nicknamed "El Guaje", is the coroner in charge of leading the investigation of those murders in the mining area.