The source material is comprised of excerpts from Peter Straub's novel, "A Dark Matter," which includes the book's table of contents and a partial list of his other works. The narrative follows an unnamed writer, Lee Harwell, who is exploring the possibility of writing a nonfiction book about an unsolved series of murders, known as the "Ladykiller" homicides, which seem connected to a "dark matter" event that traumatized his wife and friends in high school. Through conversations with his friend Donald "Dill" Olson and psychiatrist Dr. Greengrass, and later with former group member Meredith Bright Walsh, the story gradually reconstructs the 1966 events where their group, led by the charismatic Spencer Mallon, engaged in a ritual that resulted in the murder of Keith Hayward and the disappearance of Brett Milstrap, deeply affecting the lives of survivors like Howard "Hootie" Bly and Lee's wife, the "Eel." The core mystery revolves around the nature of the dark matter, the demonic figures involved, and the lasting psychological and physical damage inflicted on the participants.
