A debt owed. A woman missing. During their traumatic childhood, Madigan Knox and Detective Grace Sheppard were rescued from their abusive foster home by Officer Tina Morelli. When Morelli goes missing, Madigan and Grace connect with her daughter, eager to help in any way possible. As the suspect list grows, the detective on the case warns them to stay out of the investigation, but Morelli's daughter is convinced she knows who left the bruise she found on her mother's arm the day she disappeared. Madigan and Grace can't help but follow the leads. When the motive of one nefarious suspect implies a fate worse than death for Morelli, Madigan's investigative skills are put to the test, and on their first case together, Grace must decide what is more important—her job or finding Morelli—before it's too late and she loses both.