UPON BEING promoted to the rank of detective constable of the New Babylon Police, Leopold Orso had no idea that, from then on, he would have to track down succubae, exorcise poltergeists and hunt for werebeasts. But, even after grappling with the supernatural had become routine, he was still thrown into a trembling fear every time he thought back on his first investigation: The Case of the Bloody Tree.The Second Empire stretches from ocean to ocean. Army dirigibles hum through the heavens, and its waters are furrowed by steamships. But above all else, the power of the state is derived from industry. So one day, when workers start disappearing from a nearby factory, the New Babylon Criminal Investigation Department takes up the case. But, the detectives have no idea what horrors the acrid char of factory smokestacks can awaken...