Theorem, Pier Paolo Pasolini's third novel, could not be more different from the author and filmmaker's first novel, Boys Alive. The book began as a poem, then took shape as a film, also called Theorem, which stands as one of Pasolini's most elegant and enigmatic works for the cinema, before turning at last into a novel that bears little resemblance to any other novel. In short prose chapters interspersed with stark passages of poetry, Pasolini tells a story of transfiguration and trauma.

To the suburban mansion of a prosperous Milanese businessman comes a mysterious and beautiful young man who invites himself to stay there. From the beginning he exercises a strange fascination on the inhabitants of the house, and soon every one, from the busy father to the frustrated mother, from the yearning daughter to the weak-willed son to the house maid from the country, is sleeping with him. Then, as mysteriously as he appeared, the infatuating young man is gone. How will these people he has touched so deeply adapt to his absence? Is there a passage out of the spiritual desert of modern capitalism to an awakening, as sensual as it is spiritual? Only questions remain at the end of a book that is at once a bedroom comedy, a political intervention, and a religious parable.