Gibbs, Torres and McGee look for a missing Navy SEAL who disappeared during an unsanctioned trip, in an area of Paraguay controlled by a group of violent rebels.
Callen and Sam cross the border into Mexico and go undercover as food truck owners to find the source of an anthrax poisoning.
On Halloween, Mike and Chuck decide to spend the evening watching football instead of passing out candy with their wives.
Teresa sets out to prove her worth to Camila. Epifanio's hunt brings him closer to Teresa, and Brenda tries to hide from the cartel in Mexico.
Teresa and her crew organise a high-stakes narco horse race, but old enemies and old flames create problems and may just destroy everything.