La-bas follows the troubled novelist Durtal, disillusioned by the superficiality and crudeness of the modern world. In his quest for solace, he immerses himself in the study of the Middle Ages, becoming engrossed in the chilling history of the infamous 15th-century child-murderer, Gilles de Rais. Through his connections in Paris‚particularly with Dr. Johannes, a character inspired by Joseph-Antoine Boullan‚Durtal uncovers the unsettling truth that Satanism thrives in turn-of-the-century France. Joined by his lover, Madame Chantelouve, he delves into the shadowy realms of the occult. The novel reaches its climax with a harrowing depiction of a black mass. This gripping tale not only explores the depths of depravity and blasphemy but also depicts Durtals transformative pilgrimage, reminiscent of Dantes journey, beginning in a place steeped in horror and despair.