- "The C.I.A doesn't start what it can't finish."
- — Brian Castavin
Brian Castavin is the quaternary antagonist in Spec Ops: The Line.
He is first seen in the nest chastising one of the refugees for their use of C4 in the weakened building. He is later seen interrogating John McPherson, who takes advantage of a momentary distraction by Walker to turn his own gun on him and kill him.
He seems to be the more serious member of the team, based on his aggressive behavior. He is also the only member that is hostile towards Walker and his team, unlike Gould and Riggs.
- Castavin is named after Greg Kasavin, who was a producer on Spec Ops: The Line for about a year.
- For unknown reasons, Castavin's voice actor is not credited.