Anthropophagy—humans eating their fellow-humans—creates a curious blend of revulsion and fascination. When the perpetrator is a murderer—most commonly a sadistic serial killer—the crime is not only shocking, but also bewildering.

Moira Martingale’s comprehensive study, Cannibal Killers: The Impossible Monsters, was originally written in 1993, when the Internet was in its infancy, when few homes had computers and when the character Hannibal Lecter from the book and movie The Silence of the Lambs was regarded as an entirely fictional character, with no real-world counterparts or inspirations. The book demonstrated that this was an erroneous assumption. Translated into several languages and widely used as a resource by students studying for criminology degrees, this seminal work tracked the phenomenon of cannibalistic murderers throughout history, from the monstrous Sawney Bean, who killed and ate hundreds of travellers in Scotland five hundred years ago, to Jeffrey Dahmer, Andrei Chikatilo, Ed Kemper and Issei Sagawa—all loners, hiding their most terrible of secrets.

Then came the World Wide Web. In this comprehensively updated edition we see that in the twenty-first century cannibals who thirst for human flesh and blood are still among us, and, alarmingly, they have moved online to find their victims.