While fighting in Afghanistan, Major Grant Barrett receives devastating news: his brother and sister-in-law have been murdered in Scarlet Falls, the sleepy suburb of Grant's youth. Emotionally scarred from war, the career soldier returns home on emergency leave to temporarily care for his orphaned nephew and niece. But when someone tries to kidnap the kids and their teenage babysitter, Grant knows it's not a random act... and neither were the murders.

At the grisly murder scene of a teen prostitute, Virginia state trooper Riley Tatum's past roars back to haunt her. When she was a teenage runaway, she was kidnapped, drugged, and left unconscious on the streets. She has no memories of what happened, only strange recurring dreams of two men playing cards. Former FBI agent Clay Bowman, Riley's old flame, is Shield Security's newest member. He's plagued by the unsolved case of a serial killer nicknamed the Shark who murdered girls as part of a sadistic poker game.

Special Agent Macy Crow is a survivor. After a vicious hit-and-run nearly kills her, she gets right back to work, and now she’s gunning for a spot on the FBI’s elite profiling team. As an audition, she offers to investigate the recently discovered bones of Tobi Turner, a high school girl who disappeared fifteen years ago. While investigating with local sheriff Mike Nevada, a former colleague and onetime lover, Macy discovers a link between Tobi’s case and several others that occurred around the same time as her disappearance.

For more than twenty-five years, Philadelphia homicide detective Bree Taggert has tucked away the nightmarish childhood memories of her parents’ murder-suicide…. Until her younger sister, Erin, is killed in a crime that echoes that tragic night: innocent witnesses and a stormy marriage that ended in gunfire. There’s just one chilling difference. Erin’s husband, Justin, has vanished.

Trauma victims are not new to medical examiner Faith McIntyre, but this one is different. The unconscious woman clinging to life after a hit and run is FBI agent Macy Crow. What the woman from Quantico was doing in a dark alley after midnight is just one mystery. The other is more unsettling: Macy is Faith’s mirror image - the twin sister she never knew she had.