How many members of a family get dragged into the web of the political police on the arrest of a single political prisoner? How do you give form to someone who disappeared without having had a historical existence? Taking as its starting point the photographs taken by the Portuguese political police during the Salazar dictatorship and testimonies from those close to an assassinated communist activist, Luz Obscura invents a form that reveals how an authoritarian system operates within the family intimacy and recreates the feeling of a family's broken identity.