The Pentagon declares a security breach after the Office of Naval Intelligence discovered an online transfer of an encrypted file believed to contain classified DoD documents related to the war in Afghanistan; Callen and company investigate. Eric gets a lead to a man in Santa Monica, who specializes in governmental exposes; G and Sam, checking his pad, find his body and the missing encrypted file; G bumps into an FBI agent, and Kensi and Deeks detain two more, while Sam hustles a chick. After a squabble the FBI honcho decides to collaborate with the NCIS; Sam learns the name of the Navy petty officer, Matt, involved with the file transfer; Kensi and Deeks visit Matt's pad, where they take part in a firefight while Matt flees. Sam talks with Matt, who gives him the keyword, then bad guys arrive, and another firefight ensues, but the Hoovers arrive too late. Matt dies, but Eric, using the keyword, learns that the file contains something entirely different.