Sam expresses his trust in an old acquaintance, but is it justified, with a LOT of guns around, and, of course, some deaths? Meanwhile A.D. Mosley shows what she is worth.
LAPD Detective Whiting (Karina Logue) calls in a favor from Deeks after his former partner, LAPD Lieutenant Bates (Patrick St. Esprit), goes rogue and only Deeks can bring him in.
The team must find assailants who illegally crossed the border and attacked Border Patrol officers and illegal aliens; Homeland Security sends Nell's older and bossy sister to assist with the case.
While Hetty is being tortured by her captors in Vietnam, Eric and Nell find a clue to her whereabouts, prompting the team to organize a rescue mission with very little information. Carl Lumbly and John M. Jackson guest star.
NCIS investigates the murder of a prison inmate who was the adopted daughter of a notorious counterfeiter. Also, Callen is summoned by the (ATF) Internal Affairs board to discuss Anna's actions during a joint NCIS and ATF case.