Don Alfonso plays marimbas, the traditional Guatemalan instrument. Facing extortion and without work due to the population's lack of interest for his instrument, he seeks refuge with his godson Chiquilín. Blacko is a pioneer of the Heavy Metal Guatemalan underground stage. He is also a doctor in the public hospital but nobody wants to be treated by him because of his long hair and his tattoos. Chiquilín makes connections for Don Alfonso and Blacko to combine their talents and create a brand new band called Marimbas from Hell.