She's known as Mallory -- just Mallory -- preferring the "chilly formality" of her surname to anything else. She's intuitive, intimidating and "dangerously unstable." She can "jack up the anxiety in a room" when she enters and get what she wants before she leaves. She wears silk T-shirts, custom blazers, tailored blue jeans and shoes worth more than a car payment. She's serious, stoic and spooky. In fact, she's a sociopath. But she's also one of the more intriguing characters in the mystery genre. In "The Chalk Girl," O'Connell's 10th in this acclaimed series, Mallory investigates her most personal case to date, one as psychologically complex and disturbingly dark as she is.

Returning to New York City's special crimes unit, Mallory is the only one who can relate to Coco, a child found wandering in Central Park with blood on her shirt and a fairy tale explaining why. Mallory protects Coco in ways that stun all who know the detective, including her psychiatrist. During the investigation, Mallory and her partner, Riker, uncover a rat's nest of depravity and deceit among New York's elite and a killer who disposes of bodies in burlap bags. Each chapter is punctuated with excerpts from the diary of another lost child whose importance is not fully understood until the novel's gripping end.