After Hetty turns in retirement papers and then disappears, Executive Assistant Director Shay Mosley arrives in Los Angeles to oversee the team and immediately makes staffing changes. Also, still mourning the death of his wife and living in a trailer on the beach, Sam is adamant that Callen find a new partner.

During the murder investigation of a Navy Lieutenant on leave in Los Angeles, the NCIS team uncovers classified surveillance briefs she smuggled into the city that may have been sold to a foreign buyer.