A killer is targeting the people who matter most. When women connected to law enforcement begin turning up dead, the BAU assumes they're hunting someone seeking revenge against the justice system. But as the victim count rises, a disturbing pattern emerges: the unsub isn't choosing victims based on who they are—he's choosing them based on who would miss them. To him, every family has a heart. And every heart can be ripped out. As the investigation closes in on home, JJ, Emily, Garcia, and Y/N find themselves at the center of the unsub's twisted experiment. He's spent months studying the BAU, determining exactly whose loss would cause the most damage. Now he intends to prove his theory. And no one is safe.