90 Classic titles celebrating 90 years of Penguin Books Fabien tonight was wandering over the vast splendour of a sea of clouds, but below him lay eternity. Inspired by his career as an aviator, Saint-Exupéry's soaring novel follows the journeys of three pilots delivering mail overnight. The author's beautiful, weightless prose is as haunting as his own disappearance in flight, eerily foreshadowed by his protagonist Fabien, who becomes lost in otherworldly darkness. Letter to a Hostage, Saint-Exupéry's meditation on displacement and friendship, also explores solitude and questions the human condition.