The libretto, written by the composer, is based on Erich Fried's German translation of John Whiting's dramatization of Aldous Huxley's essay "The Devils of Loudun". The employment of existing literature as the basis for the librettos was not exclusive to "The Devils of Loudun"; instead, it became the invariant among Penderecki's four operas; namely "Paradise Lost", "Ubu Rex", and "Die schwarze Maske". The libretto is written in German (although both Polish and English adaptations exist) and it is fashioned into a series of thirty two scenes, which proceed, from one to another, quasi cinematically.