The true-crime cult classic that inspired the Netflix docuseries The Sons of Sam: A Descent into Darkness and a companion podcast, The Ultimate Evil follows journalist Maury Terry's decades-long investigation into the terrifying truth behind the Son of Sam murders. On August 10, 1977, the NYPD arrested David Berkowitz for the Son of Sam murders that had terrorized New York City for over a year. Berkowitz confessed to shooting sixteen people and killing six with a .44 caliber Bulldog revolver, and the case was officially closed. Journalist Maury Terry was suspicious of Berkowitz's confession. Spurred by conflicting witness descriptions of the killer and clues overlooked in the investigation, Terry was convinced Berkowitz didn't act alone. Meticulously gathering evidence for a decade, he released his findings in the first edition of The Ultimate Evil. Based upon the evidence he had uncovered, Terry theorized that the Son of Sam attacks were masterminded by a Yonkers-based cult that was responsible for other ritual murders across the country. After Terry's death in 2015, documentary filmmaker Josh Zeman (Cropsey, The Killing Season, Murder Mountain) was given access to Terry's files, which form the basis of his docuseries with Netflix and a companion podcast. Taken together with The Ultimate Evil, which includes a new introduction by Zeman, these works reveal the stunning intersections of power, wealth, privilege, and evil in America--from the Summer of Sam until today.