Callen and Sam fly to Idaho and join forces with NCIS: Red, a mobile team of agents who live together and investigate crimes in various locations, when a murder weapon found there matches one used in a national security case in Los Angeles.

While the LA team chases leads digitally and locally, the NCIS: Red team travels in their mobile trucks, nicknamed "Laverne and Shirley", in a race to track down a cunning terrorist before he disappears.

After the U.S. Treasury Department is hacked, Nell and Eric go undercover inside a couple's retreat to track a tech-savvy husband and wife linked to the crime. Also, Digital Forensics Specialist Dave Flynn (Scott Grimes) arrives from the NCIS cyber office in San Diego to run ops while Eric and Nell are on assignment.