Billy Gibbons from ZZ Top sits in with the band; Dave, Tony, Rupert, and Alan have fun with sirens; Jane Fonda discusses her marriage to Ted Turner; Shooter Jennings performs "Gone to Carolina."
When a Pentagon cryptographer is found dead, the NCIS team has to discover whether the person was or wasn't a Pentagon mole, and if the person committed suicide. As the investigation continues, the team discovers that the person wasn't alone when she died, so someone must have murdered her. So, the team has to find the person, a mole, who murdered the cryptographer.
The crew must fly to Afghanistan to assassinate a high ranking member of the Taliban. However, one of their team helicopters ends up going down in enemy territory, placing the entire crew in jeopardy. Back at the base, Molly confronts a friend and retired Unit veteran about his addiction to painkillers and Kim ends up getting a job at the local radio station.