1934 - los mineros asturianos se rebelan contra su situación social y en la creencia de que en Cataluña, Andalucía y Madrid les apoyan, se levantan en armas contra la Guardia Civil y el ejército, llegando a conquistar la capital: Oviedo. Mientras esto ocurre, el forense de la Guardia Civil, ante la ausencia de efectivos en el cuerpo, debe encargarse de investigar y descubrir a un asesino en serie. Cada asesinato que comete va emparejado a un ser de la mitología asturiana. Dos hermanos de una familia minera y humilde se ven envueltos en la lucha de ese rojo mes de octubre.
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.