Following Monica Rawlings' departure, Steve Billings assumes command of the Barn just as a campus race riot leaves a Latino high school student dead. As the shooting challenges the new leadership, Vic comes under the scrutiny of Jon Kavanaugh, an Internal Affairs investigator obsessed with exposing the Strike Team's crimes. Determined to charge Vic with Agent Terry Crowley's murder, Kavanaugh enlists Aceveda's help and threatens Lem, Corrine and an informant to gain their cooperation, too. With investigations into sex trafficking and the Money Train Heist taxing the Barn's limited resources, Claudette's admission that she has been hiding a serious illness and Danny's refusal to identify her baby's father add to the tension. Yet, with Kavanaugh's own skeletons undermining his credibility, Vic seeks help from a defense lawyer as he is stunned by Lem's murder at the hands of a fellow cop.