Both Sinclair and Ackroyd's ideas in turn were further developed by Alan Moore and Eddie Campbell in their graphic novel, "From Hell", which speculated that Jack the Ripper used Hawksmoor's buildings as part of ritual magic, with his victims as human sacrifice. In the appendix, Moore revealed that he had met and spoken with Sinclair on numerous occasions while developing the core ideas of the book. The argument includes the idea that the locations of the churches form a pentagram with ritual significance.