“I was married to a crime fighter for a decade,” writes Patton Oswalt in describing his late wife, Michelle McNamara. “She was born with a true cop’s heart and mind… She made everything about me and everyone around her better. And she did it by being quietly, effortlessly original.” I’ll Be Gone in the Dark—the book McNamara was writing at the time of her sudden death—offers an atmospheric snapshot of a moment in American history and a chilling account of a criminal mastermind and the wreckage he left behind. It is also a portrait of a woman’s obsession and her unflagging pursuit of the truth. Framed by an introduction by Gillian Flynn and an afterword by her husband, Patton Oswalt, the book was completed by Michelle’s lead researcher and a close colleague. It is destined to become a true crime classic—and may at last help unmask the Golden State Killer.