A "Victorian-era Hannibal Lecter," Edward Rulloff was a clever but completely immoral murderer whose crimes spanned decades and whose victims were picked out of retaliation, envy, and occasionally need. Rulloff used his cunning and regal demeanor to avoid detection and punishment at every turn, from his lowly beginnings in upstate New York to the opulent salons and social life he developed in New York City. Rulloff could always talk his way out of a situation, but eventually his good fortune ran out. By 1871, Rulloff was a psychopath sitting court in his chained cell as inquisitive 19th-century "mindhunters" tried to figure out what made him tick. Each one believed he held the answer to the fundamental question: Is evil born or made? From alienists (early psychiatrists who sought to understand the cause of his madness) to neurologists (who sought to examine his brain) to phrenologists (who examined the bumps on his head to determine his character). Rulloff's brain was eventually preserved as the prize specimen for their anatomy collection at Cornell University, where it is still kept today, slowly rotting in a dusty container. However, his tale-and its ramifications for the nascent discipline of criminal psychology-were just getting started. In ALL THAT IS DARK, which was expanded from season one of her popular podcast on the Exactly Right network (with seven million downloads and counting), In order to present one of the earliest glimpses into the mind of a serial killer-a century before the term was coined-through the scientists whose work would come to influence criminal justice for decades to come, Hilary Anderson draws on hundreds of sources, including previously unpublished historical documents.