We first met John Douglas in Mindhunter, telling the story of his brilliant and terrifying career with the FBI, until his retirement in 1995. And now, working again with coauthor Mark Olshaker, acclaimed filmmaker, novelist, and journalist, John takes us even further. We accompany him on the Journey into Darkness, for every instance that helps police identify the unknown subject of a violent series of rapes, bombings, arsons, or murders is another trip to the dark side. And here we travel with some of the brilliant and sensitive agent trained, and who have carried on the work: men like Jud Ray, who by phone gave Alaska the police the exact personality of the killer of a mother and her two young daughters; Gregg McCrary, who confronted an unknown killer of teenagr girls on national television and assured him he would be caught; and Steve Marfigian, who formulated a complex strategy for solving a years-old string of burglaries, rapes, and murders, and in the process helped free the wrong convicted man.