Jon Kavanaugh is a lieutenant in Internal Affairs at the LAPD who is determined to bring Vic Mackey down. He is compelled by a personal goal to advance his own career by bringing down one of the city's most crooked cops. Kavanaugh has a history of turning on other cops, having broken the accepted code of silence against a former partner. Kavanaugh's efforts to nail Mackey soon turn extremely personal -- to the point that Kavanaugh very aggressively involves Mackey's ex-wife Corrine in his effort to settle the score.