As the Strike Team battles racial tensions in the city, friction inside The Barn escalates with the arrival of Lieutenant Jon Kavanaugh (Forest Whitaker), an dogged Internal Affairs cop obsessed with taking down down Vic Mackey, squeezing Vic's ex-wife Corrine, to do it. In the midst of this chaos, Dutch and Claudette's work relationship becomes strained, Danny refuses to reveal the father of her baby and Julien struggles with a new, attractive rookie partner.