
When a meticulous killer begins targeting women and stealing their phones, FBI behavioral analyst Grace Billingsley recognizes the patterns—and the rage—behind his ritual. The case pulls prison psychiatrist Sam Monroe into the hunt for an unnerving reason: his father is the infamous Cell Phone Killer, now incarcerated but still casting a long shadow. As Grace and Sam compare evidence, a subtle turn reveals the killer has been hiding in plain sight, watching crime scenes through victims’ devices and taking detailed pride in every decision. A hostage crisis at a federal prison, a near‑fatal abduction at a hospital, and a terrifying confrontation in Grace’s own home push them from analysis to survival. Along the way, Sam’s complicated home life and Grace’s painful family history crack open, forcing them to face their past while protecting the people they love. When the hunt finally exposes a twisted alliance inside the system and a copycat determined to impress a monster, Grace must outthink a man who believes he’s executing justice—one silenced voice at a time.