McCall receives a desperate plea for help from her former CIA trainee, now a full-fledged agent, that leads her into a confrontation with Mason Quinn, the most dangerous enemy from her past in intelligence. In need of confidential information about the agent's latest assignment, McCall forms a tentative alliance with Carter Griffin, a by-the-book CIA handler.

When Aunt Vi is the lone juror on a murder trial who believes the defendant is innocent, McCall covertly investigates the case to find proof that Vi's instincts are correct.