Nell joins Deeks in the field on a case involving a former Marine who is being tracked by al-Qaida.

The team takes an undercover agent who is suspected of working for a smuggler into custody.

Software for an unmanned aerial vehicle goes missing, along with the lead engineer's daughter.

A deadly explosion takes place at a charity event sponsored by the military.

The team discovers the cartel's plan to transport cocaine to the U.S. using a submarine.

The team tries to find Callen and Sam, who are trapped in a submarine aimed at an aircraft carrier.

The team investigates the murder of a Navy contractor involved with selling confidential data.

A member of the team is targeted by the Department of Justice; Hetty receives disturbing news.

A desperate search begins when the team learns that one of their own is being targeted.

Callen and Sam hunt for an employee of the Department of Defense after a shooting.

Callen and Granger try to clear Sam's name after he's arrested for a woman's murder.

When a Russian bomber goes missing while flying over U.S. soil, Callen and Sam must track it down in the desert and secure its weapons and intel before the Russians on board destroy the plane. Also, Hetty gives Nell a cryptic assignment.