This book is about late nights in dark garrets, intelligent discussions on the practice of satanism, and the imperious power of sexual dreams. The hero, Durtal, is writing a biography of Bluebeard- that Gilles de Rais who was both a Marshall of France and the killer of so many children at Tiffauges castle. The subject matter unbalances Durtal and he is himself driven towards exploring the darkness, as he attends the Black Mass. I recommend it highly to those looking for unusual books, and the decadent fringes of C19th Paris. La Bas is part of a trilogy in which Durtal appears to lose himself and then comes back to God, in the second volume, after a stay at the Monastery of La Trappe (for which read 'En Route').