When NCIS investigates the murder of a man about to reveal the source of a massive counterfeiting operation, an old acquaintance becomes their prime suspect and reveals the true reason for her return. Also, Deeks struggles during training to become an official NCIS agent.

When a torpedo hits a fishing trawler at sea, the entire Gulf Coast is in jeopardy as Pride and NCIS race to find the submarine before it can strike again.

The Milkoviches move in next door and wreak havoc, leading Frank, Kev and Liam to plot how to get rid of them. Mickey embarks on a new security gig for Kev and V and drags Ian along against his will. V and Debbie turn into stage moms when Gemma and Franny compete in the Little Miss South Side beauty pageant. Lip gets a big surprise when he reluctantly agrees to go to brunch with Tami and her old high school music teacher. When Carl’s training officer is overly aggressive, Carl is forced to choose between his job and his neighborhood.