Mateo lives with his mother Libertad in a rose-tinted world: a microcosm which has precisely two inhabitants, mother and son. One day Mateo is diagnosed with cancer… There are few films which defy all the rules in order to tell an utterly realistic story, and Piety is one of them. We find ourselves in a reality where the mother exercises the same kind of power as the dictator governing North Korea. Just as toxic, just as absolute, and just as deadly.