When an FBI agent is killed while trying to track the location of an undercover agent, NCIS must find the missing agent before the criminals he was investigating do

Before Christmas, Hetty assigns Callen the case of his former foster brother and his wife who, upon reentry into the U.S., are framed for smuggling drugs across the border in her oxygen tanks. Also, Deeks is struggling with losing his job at NCIS.

When NCIS investigates the murder of a man about to reveal the source of a massive counterfeiting operation, an old acquaintance becomes their prime suspect and reveals the true reason for her return. Also, Deeks struggles during training to become an official NCIS agent