Olmos is a corporal of the Civil Guard's Public Order and Prevention service who works in the station of his birthplace, Ezcaray, a small town in La Rioja. Robles is a lieutenant of the Rapid Reaction Group, one of the most prestigious units of the Civil Guard, an urban and modern officer. They see themselves forced to work together if they want to solve the international case which, as luck would have it, has united them in this town in La Rioja. They are polar opposites, but together they make up a great team.