Javier Salazar is a prominently featured character in Call of Duty: Black Ops II. Even though he appears as a friendly character for most of the game, he reveals his true colors as a double agent working for Cordis Die during the campaign level "Odysseus" when he betrays Admiral Briggs and murders (according to past player actions) either Farid or Chloe Lynch.
Later during the same level, he is encountered by David Mason (and Mike Harper, if he is still alive) and confesses his betrayal, saying, "Today is a difficult day, Section. Tomorrow, we all win." If Harper is still alive, he will execute Salazar on the spot.