July 31,1784, Paris. Denis Diderot has just passed away and with him, the memory of the biggest editorial epic of the Age of Enlightenment : Encyclopedia, or a Systematic Dictionary of the Sciences, Arts and Crafts. This monumental œuvre is before anything else the result of the fight of a man against obscurantism and of his unfailing trust in reason. Carried by men such as Voltaire or Rousseau, the adventure will last 25 years. It will encounter numerous unforeseen developments and end in clandestinity but won’t fail to revolutionize the publishing world.