David Berkowitz is the only person ever charged with the infamous Son of Sam murders in New York City during 1976-77. But what about the Yonkers-based satanic cult of which Berkowitz claims to have been a member? Is there any evidence that such a cult existed and had already been active for many years when the Sam shootings began? Before Son of Sam definitively answers that question. In my novel The Agent I wrote about a fictionalized version of the cult; this is the bizarre, terrifying reality.