She falls asleep to stories of mystery and true crime. She has a podcast for the commute, a docuseries for the weekend, and a theory about your new coworker she hasn't shared yet. And you-lying awake beside her, listening to that calm voice describing terrible things-have quietly wondered what, exactly, is going on.

Here is the answer, from a forensic psychologist who is also a lifelong fan. The woman you love isn't morbid, and she's in no danger of becoming so. She's doing something ancient and ingenious: studying the worst the world can do so she'll be ready for it, taming her fear by giving it edges, and joining a sisterhood of women who have always had to pay closer attention than you ever did.

True Crime Soothes the Soul explains what she's actually doing-the fear, the rehearsal, the community, the quiet civic good of the genre-and then teaches you to stop standing in the doorway and pull up a chair beside her. You don't have to love what she loves. You only have to understand it. By the last page, you will, and you'll know exactly what to do about it.

Dr. Crystal Hernandez has been obsessed with true crime since she was young, when a television show she was not supposed to be watching reached into her chest and refused to let go. Dr. Hernandez went on to study the subject formally, earning a doctoral degree in forensic psychology, and has spent her adult life on both sides of the glass as a trained student of why people do terrible things and as an unrepentant fan of the podcasts, documentaries, books, and conventions that ask the same question for fun. She still falls asleep to murder most nights and she sleeps extremely well.Dr. Hernandez wrote True Crime Soothes the Soul because she grew tired of trying to answer the same question-usually from a slightly nervous man. It's the long version of that answer, written and printed, so she can hand it over and get back to her episode.Dr. Hernandez would like the record to show that she has been asked more than once whether writing this book required her to defend something indefensible. To that, her answer is no. It required her to defend something ordinary, human, and brave-something the world has never bothered to understand. After all the study over the years, she remains exactly who she was on that carpet long past her bedtime: a person who would rather look directly at the dark and understand it than pretend, for the sake of someone else's comfort, that it isn't there. As you read this, she's almost certainly listening to a story of true crime. She would tell you it's fine. And it is.