Callen, Sam, Kensi and Deeks join Hetty’s team from the Vietnam War, Sterling Bridges, A.J. Chegwidden and Charles Langston, in a dangerous and off-the-books rescue mission to save Hetty from her captors in Vietnam. Mosley calls in Nell’s sister, a homeland security, to assist the team in Los Angeles with processing evidence connected to Hetty’s time in Vietnam.